Method for controlling uplink transmission power in wireless communication system and device therefor

ABSTRACT

The present invention relates to a method for controlling uplink transmission power of a terminal in a wireless communication system, the method comprising the steps of: transmitting an uplink signal according to a predetermined uplink-downlink configuration with respect to a serving cell, receiving first transmission power control information for a first set of uplink sub-frames and second transmission power control information for a second set of uplink sub-frames from the serving cell, and transmitting a physical uplink shared channel (PUSCH) on a particular sub-frame included in the second set of uplink sub-frames, according to the second transmission power control information, wherein the second set of uplink sub-frames is configured by at least one uplink sub-frame specified by a upper layer signaling among a plurality of uplink sub-frames according to the predetermined uplink-downlink configuration.

TECHNICAL FIELD

The present invention relates to a wireless communication system, andmore particularly, to a method of controlling uplink transmission powerin a wireless communication system and an apparatus therefor.

BACKGROUND ART

A 3rd generation partnership project long term evolution (3GPP LTE)(hereinafter, referred to as ‘LTE’) communication system which is anexample of a wireless communication system to which the presentinvention can be applied will be described in brief.

FIG. 1 is a diagram illustrating a network structure of an EvolvedUniversal Mobile Telecommunications System (E-UMTS) which is an exampleof a wireless communication system. The E-UMTS is an evolved version ofthe conventional UMTS, and its basic standardization is in progressunder the 3rd Generation Partnership Project (3GPP). The E-UMTS may bereferred to as a Long Term Evolution (LTE) system. Details of thetechnical specifications of the UMTS and E-UMTS may be understood withreference to Release 7 and Release 8 of “3rd Generation PartnershipProject; Technical Specification Group Radio Access Network”.

Referring to FIG. 1, the E-UMTS includes a User Equipment (UE), basestations (eNode B; eNB), and an Access Gateway (AG) which is located atan end of a network (E-UTRAN) and connected to an external network. Thebase stations may simultaneously transmit multiple data streams for abroadcast service, a multicast service and/or a unicast service.

One or more cells exist for one base station. One cell is set to one ofbandwidths of 1.44, 3, 5, 10, 15 and 20 MHz to provide a downlink oruplink transport service to several user equipments. Different cells maybe set to provide different bandwidths. Also, one base station controlsdata transmission and reception for a plurality of user equipments. Thebase station transmits downlink (DL) scheduling information of downlinkdata to the corresponding user equipment to notify the correspondinguser equipment of time and frequency domains to which data will betransmitted and information related to encoding, data size, and hybridautomatic repeat and request (HARQ). Also, the base station transmitsuplink (UL) scheduling information of uplink data to the correspondinguser equipment to notify the corresponding user equipment of time andfrequency domains that can be used by the corresponding user equipment,and information related to encoding, data size, and HARQ. An interfacefor transmitting user traffic or control traffic may be used between thebase stations. A Core Network (CN) may include the AG and a network nodeor the like for user registration of the user equipment. The AG managesmobility of the user equipment on a Tracking Area (TA) basis, whereinone TA includes a plurality of cells.

Although the wireless communication technology developed based on WCDMAhas been evolved into LTE, request and expectation of users andproviders have continued to increase. Also, since another wirelessaccess technology is being continuously developed, new evolution of thewireless communication technology will be required for competitivenessin the future. In this respect, reduction of cost per bit, increase ofavailable service, use of adaptable frequency band, simple structure andopen type interface, proper power consumption of the user equipment,etc. are required.

Recently, ongoing effort to standardize a follow-up technology for LTEis in progress by 3GPP. In the present specification, the technology isreferred to as ‘LTE-A’. LTE-A system aims to support a wideband ofmaximum 100 MHz. To this end, the LTE-A system uses a carrieraggregation (CA) technology to achieve the wideband using a plurality offrequency blocks. In order to use a wider frequency band, the CA uses aplurality of the frequency blocks as a single huge logical frequencyband. A bandwidth of each frequency block can be defined based on abandwidth of a system block used in LTE system. Each of a plurality ofthe frequency blocks can be referred to as a component carrier (CC) or acell.

And, in LTE system, it is able to support a duplex operation fordividing all available resources into a downlink resource (i.e., aresource used by a base station to transmit a signal to a UE) and anuplink resource (i.e., a resource used by a UE to transmit a signal to abase station). For example, a frequency division duplex (FDD) scheme ora time division duplex (TDD) scheme can be applied. A usage of eachresource can be configured as either downlink (DL) or uplink (UL).According to legacy LTE system, the usage is designated by systeminformation.

Recently, as one of methods of improving LTE/LTE-A system, regarding theduplex operation, discussion on a method of dynamically designatingDL-UL configuration is in progress.

DISCLOSURE OF THE INVENTION Technical Task

Based on the aforementioned discussion, the present invention proposes amethod of controlling uplink transmission power in a wirelesscommunication system and an apparatus therefor in the followingdescription.

Technical tasks obtainable from the present invention are non-limitedthe above-mentioned technical task. And, other unmentioned technicaltasks can be clearly understood from the following description by thosehaving ordinary skill in the technical field to which the presentinvention pertains.

Technical Solution

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, accordingto one embodiment, a method of controlling uplink transmission power,which is controlled by a user equipment in a wireless communicationsystem, includes the steps of transmitting an uplink signal according toan uplink-downlink configuration predetermined to a serving cell,receiving first transmission power control information on a first uplinksubframe set and second transmission power control information on asecond uplink subframe set from the serving cell and transmitting anuplink data channel (physical uplink shared channel (PUSCH)) in aspecific subframe included in the second uplink subframe set accordingto the second transmission power control information. In this case, thesecond uplink subframe set includes at least one or more uplinksubframes designated by higher layer signaling among a plurality ofuplink subframes according to the predetermined uplink-downlinkconfiguration.

Moreover, the second transmission power control information can includea value indicating a current PUSCH power control adjustment state for anindex of the specific subframe.

Moreover, if information on the second uplink subframe set is received,the current PUSCH power control adjustment state can be reset.

Moreover, if information on the second uplink subframe set is received,the current PUSCH power control adjustment state can be set to 0.

Moreover, the first uplink subframe set may correspond to a subframe ofwhich a usage of a radio resource is configured not to be changed andthe second uplink subframe set may correspond to a subframe of which ausage of a radio resource is configured to be changed.

Moreover, the first uplink subframe set and the second uplink subframeset may be different from each other in an interference characteristicwith a neighbor cell.

Moreover, the second uplink subframe set can be indicated by a usagechange message.

Moreover, the specific subframe can be indicated by downlink controlinformation in a DCI format 0/4.

To further achieve these and other advantages and in accordance with thepurpose of the present invention, according to a different embodiment, auser equipment controlling uplink transmission power in a wirelesscommunication system can include a radio frequency unit and a processor,the processor configured to transmit an uplink signal according to anuplink-downlink configuration predetermined to a serving cell, theprocessor configured to receive first transmission power controlinformation on a first uplink subframe set and second transmission powercontrol information on a second uplink subframe set from the servingcell, the processor configured to transmit an uplink data channel(physical uplink shared channel (PUSCH)) in a specific subframe includedin the second uplink subframe set according to the second transmissionpower control information. In this case, the second uplink subframe setincludes at least one or more uplink subframes designated by higherlayer signaling among a plurality of uplink subframes according to thepredetermined uplink-downlink configuration.

Advantageous Effects

According to embodiments of the present invention, a UE is able toefficiently control uplink transmission power in a wirelesscommunication system.

Effects obtainable from the present invention may be non-limited by theabove mentioned effect. And, other unmentioned effects can be clearlyunderstood from the following description by those having ordinary skillin the technical field to which the present invention pertains.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

FIG. 1 is a schematic diagram of E-UMTS network structure as one exampleof a wireless communication system;

FIG. 2 is a diagram illustrating structures of a control plane and auser plane of a radio interface protocol between a user equipment andE-UTRAN based on the 3GPP radio access network standard;

FIG. 3 is a diagram illustrating physical channels used in a 3GPP LTEsystem and a general method for transmitting a signal using the physicalchannels;

FIG. 4 is a diagram illustrating a structure of a downlink radio frameused in an LTE system;

FIG. 5 is a diagram illustrating a structure of an uplink subframe usedin an LTE system;

FIG. 6 is a diagram for an example of a structure of a radio frame inLTE TDD system;

FIG. 7 is a conceptual diagram for explaining a carrier aggregationtechnique;

FIG. 8 is a diagram for an example of dividing a radio frame into asubframe set #1 and a subframe set #2 according to a change of a usageof a radio resource;

FIG. 9 is a block diagram for a communication device according to oneembodiment of the present invention.

BEST MODE Mode for Invention

In the following, configuration, action and other characteristics of thepresent invention can be easily understood by embodiments of the presentinvention which are explained with reference to attached drawings. Theembodiments explained in the following correspond to examples of whichtechnological characteristics of the present invention are applied to3GPP system.

In the present specification, although the embodiments of the presentinvention will be described based on the 3GPP LTE/LTE-A, the embodimentsof the present invention can be applied to any communication systemcorresponding to the aforementioned definition. And, in the presentspecification, a name of a base station is used by a comprehensiveterminology including an RRH (remote radio head), a TP (transmissionpoint), an RP (reception point), an eNB, a relay and the like.

FIG. 2 is a diagram illustrating structures of a control plane and auser plane of a radio interface protocol between a user equipment andE-UTRAN based on the 3GPP radio access network standard. The controlplane means a passageway where control messages are transmitted, whereinthe control messages are used by the user equipment and the network tomanage call. The user plane means a passageway where data generated inan application layer, for example, voice data or Internet packet dataare transmitted.

A physical layer as the first layer provides an information transferservice to an upper layer using a physical channel. The physical layeris connected to a medium access control (MAC) layer via a transportchannel, wherein the medium access control layer is located above thephysical layer. Data are transferred between the medium access controllayer and the physical layer via the transport channel. Data aretransferred between one physical layer of a transmitting side and theother physical layer of a receiving side via the physical channel. Thephysical channel uses time and frequency as radio resources. In moredetail, the physical channel is modulated in accordance with anorthogonal frequency division multiple access (OFDMA) scheme in adownlink, and is modulated in accordance with a single carrier frequencydivision multiple access (SC-FDMA) scheme in an uplink.

A medium access control (MAC) layer of the second layer provides aservice to a radio link control (RLC) layer above the MAC layer via alogical channel. The RLC layer of the second layer supports reliabledata transmission. The RLC layer may be implemented as a functionalblock inside the MAC layer. In order to effectively transmit data usingIP packets such as IPv4 or IPv6 within a radio interface having a narrowbandwidth, a packet data convergence protocol (PDCP) layer of the secondlayer performs header compression to reduce the size of unnecessarycontrol information.

A radio resource control (RRC) layer located on the lowest part of thethird layer is defined in the control plane only. The RRC layer isassociated with configuration, re-configuration and release of radiobearers (‘RBs’) to be in charge of controlling the logical, transportand physical channels. In this case, the RB means a service provided bythe second layer for the data transfer between the user equipment andthe network. To this end, the RRC layers of the user equipment and thenetwork exchange RRC message with each other. If the RRC layer of theuser equipment is RRC connected with the RRC layer of the network, theuser equipment is in an RRC connected mode. If not so, the userequipment is in an RRC idle mode. A non-access stratum (NAS) layerlocated above the RRC layer performs functions such as sessionmanagement and mobility management.

One cell constituting a base station eNB is set to one of bandwidths of1.4, 3.5, 5, 10, 15, and 20 MHz and provides a downlink or uplinktransmission service to several user equipments. At this time, differentcells may be set to provide different bandwidths.

As downlink transport channels carrying data from the network to theuser equipment, there are provided a broadcast channel (BCH) carryingsystem information, a paging channel (PCH) carrying paging message, anda downlink shared channel (SCH) carrying user traffic or controlmessages. Traffic or control messages of a downlink multicast orbroadcast service may be transmitted via the downlink SCH or anadditional downlink multicast channel (MCH). Meanwhile, as uplinktransport channels carrying data from the user equipment to the network,there are provided a random access channel (RACH) carrying an initialcontrol message and an uplink shared channel (UL-SCH) carrying usertraffic or control message. As logical channels located above thetransport channels and mapped with the transport channels, there areprovided a broadcast control channel (BCCH), a paging control channel(PCCH), a common control channel (CCCH), a multicast control channel(MCCH), and a multicast traffic channel (MTCH).

FIG. 3 is a diagram illustrating physical channels used in a 3GPP LTEsystem and a general method for transmitting a signal using the physicalchannels.

The user equipment performs initial cell search such as synchronizingwith the base station when it newly enters a cell or the power is turnedon at step S301. To this end, the user equipment synchronizes with thebase station by receiving a primary synchronization channel (P-SCH) anda secondary synchronization channel (S-SCH) from the base station, andacquires information such as cell ID, etc. Afterwards, the userequipment may acquire broadcast information within the cell by receivinga physical broadcast channel (PBCH) from the base station. Meanwhile,the user equipment may identify a downlink channel status by receiving adownlink reference signal (DL RS) at the initial cell search step.

The user equipment which has finished the initial cell search mayacquire more detailed system information by receiving a physicaldownlink shared channel (PDSCH) in accordance with a physical downlinkcontrol channel (PDCCH) and information carried in the PDCCH at stepS302.

Afterwards, the user equipment may perform a random access procedure(RACH) such as steps S303 to S306 to complete access to the basestation. To this end, the user equipment may transmit a preamble througha physical random access channel (PRACH) (S303), and may receive aresponse message to the preamble through the PDCCH and the PDSCHcorresponding to the PDCCH (S304). In case of a contention based RACH,the user equipment may perform a contention resolution procedure such astransmission (S305) of additional physical random access channel andreception (S306) of the physical downlink control channel and thephysical downlink shared channel corresponding to the physical downlinkcontrol channel.

The user equipment which has performed the aforementioned steps mayreceive the physical downlink control channel (PDCCH)/physical downlinkshared channel (PDSCH) (S307) and transmit a physical uplink sharedchannel (PUSCH) and a physical uplink control channel (PUCCH) (S308), asa general procedure of transmitting uplink/downlink signals. Inparticular, the user equipment receives downlink control information(DCI) through the PDCCH. In this case, the DCI includes controlinformation such as resource allocation information on the UE and aformat of the DCI may vary according to a usage of the DCI.

Meanwhile, control information transmitted to a base station by a UE inUL or control information received from the base station by the UEincludes DL/UL ACK/NACK signal, a CQI (channel quality indicator), a PMI(precoding matrix index), an RI (rank indicator), etc. in 3GPP LTEsystem, the UE can transmit the aforementioned control information suchas the CQI/PMI/RI via the PUSCH and/or the PUCCH.

FIG. 4 is a diagram for a control channel included in a control regionof a subframe in a downlink radio frame.

Referring to FIG. 4, a subframe includes 14 OFDM symbols. The first oneto three OFDM symbols of a subframe are used for a control region andthe other 13 to 11 OFDM symbols are used for a data region according toa subframe configuration. In FIG. 4, reference characters R1 to R4denote RSs or pilot signals for antenna 0 to antenna 3. RSs areallocated in a predetermined pattern in a subframe irrespective of thecontrol region and the data region. A control channel is allocated tonon-RS resources in the control region and a traffic channel is alsoallocated to non-RS resources in the data region. Control channelsallocated to the control region include a physical control formatindicator channel (PCFICH), a physical hybrid-arq indicator channel(PHICH), a physical downlink control channel (PDCCH), etc.

The PCFICH is a physical control format indicator channel carryinginformation about the number of OFDM symbols used for PDCCHs in eachsubframe. The PCFICH is located in the first OFDM symbol of a subframeand configured with priority over the PHICH and the PDCCH. The PCFICH iscomposed of 4 resource element groups (REGs), each REG being distributedto the control region based on a cell identity (ID). One REG includes 4resource elements (REs). An RE is a minimum physical resource defined byone subcarrier by one OFDM symbol. The PCFICH indicates 1 to 3 or 2 to 4according to a bandwidth. The PCFICH is modulated in quadrature phaseshift keying (QPSK).

The PHICH is a physical hybrid-automatic repeat and request (HARQ)indicator channel carrying an HARQ ACK/NACK for an uplink transmission.That is, the PHICH is a channel that delivers DL ACK/NACK informationfor UL HARQ. The PHICH includes one REG and is scrambledcell-specifically. An ACK/NACK is indicated in one bit and modulated inbinary phase shift keying (BPSK). The modulated ACK/NACK is spread witha Spreading Factor (SF) of 2 or 4. A plurality of PHICHs mapped to thesame resources form a PHICH group. The number of PHICHs multiplexed intoa PHICH group is determined according to the number of spreading codes.A PHICH (group) is repeated three times to obtain a diversity gain inthe frequency domain and/or the time domain.

The PDCCH is a physical downlink control channel allocated to the firstn OFDM symbols of a subframe. Here, n is 1 or a larger integer indicatedby the PCFICH. The PDCCH is composed of one or more CCEs. The PDCCHcarries resource allocation information about transport channels, PCHand DL-SCH, an uplink scheduling grant, and HARQ information to each UEor UE group. The PCH and the DL-SCH are transmitted on a PDSCH.Therefore, an eNB and a UE transmit and receive data usually on thePDSCH, except for specific control information or specific service data.

Information indicating one or more UEs to receive PDSCH data andinformation indicating how the UEs are supposed to receive and decodethe PDSCH data are delivered on a PDCCH. For example, on the assumptionthat the cyclic redundancy check (CRC) of a specific PDCCH is masked byradio network temporary identity (RNTI) “A” and information about datatransmitted in radio resources (e.g. at a frequency position) “B” basedon transport format information (e.g. a transport block size, amodulation scheme, coding information, etc.) “C” is transmitted in aspecific subframe, a UE within a cell monitors, that is, blind-decodes aPDCCH using its RNTI information in a search space. If one or more UEshave RNTI “A”, these UEs receive the PDCCH and receive a PDSCH indicatedby “B” and “C” based on information of the received PDCCH.

FIG. 5 illustrates a structure of a UL subframe in the LTE system.

Referring to FIG. 5, a UL subframe may be divided into a control regionand a data region. A physical uplink control channel (PUCCH) includinguplink control information (UCI) is allocated to the control region anda physical uplink shared channel (PUSCH) including user data isallocated to the data region. The middle of the subframe is allocated tothe PUSCH, while both sides of the data region in the frequency domainare allocated to the PUCCH. Control information transmitted on the PUCCHmay include an HARQ ACK/NACK, a CQI representing a downlink channelstate, an RI for multiple input multiple output (MIMO), a schedulingrequest (SR) requesting UL resource allocation. A PUCCH for one UEoccupies one resource block (RB) having a different frequency in eachslot of a subframe. That is, the two RBs allocated to the PUCCHfrequency-hop over the slot boundary of the subframe. Particularly,PUCCHs with m=0, m=1, m=2, and m=3 are allocated to a subframe in FIG.5.

Time for which a sounding reference signal is transmittable correspondsto a section at which a symbol positioned at the very last on a timeaxis is positioned in a subframe. A sounding reference signal istransmitted through a data transmission band on a frequency axis.Sounding reference signals of several user equipments, which aretransmitted through the last symbol of an identical subframe, can bedistinguished from each other according to a frequency position.

FIG. 6 illustrates a structure of a radio frame in an LTE TDD system. Inthe LTE TDD system, a radio frame includes two half frames, and eachhalf frame includes four normal subframes each including two slots, anda special subframe including a downlink pilot time slot (DwPTS), a guardperiod (GP), and an uplink pilot time slot (UpPTS).

In the special subframe, the DwPTS is used for initial cell search,synchronization, or channel estimation in a UE. The UpPTS is used forchannel estimation in an eNB and uplink transmission synchronization ofa UE. That is, the DwPTS is used for downlink transmission and the UpPTSis used for uplink transmission. In particular, the UpPTS is used fortransmission of a PRACH preamble or SRS. In addition, the GP is a periodfor removing interference generated in uplink due to multipath delay ofa downlink signal between uplink and downlink.

Meanwhile, in an LTE TDD system, a UL/DL configuration is shown in Table1 below.

TABLE 1 Uplink- Downlink- downlink to-Uplink config- Switch-pointSubframe number uration periodicity 0 1 2 3 4 5 6 7 8 9 0 5 ms D S U U UD S U U U 1 5 ms D S U U D D S U U D 2 5 ms D S U D D D S U D D 3 10 ms D S U U U D D D D D 4 10 ms  D S U U D D D D D D 5 10 ms  D S U D D D DD D D 6 5 ms D S U U U D S U U D

In the above Table 1, D indicates a downlink subframe, U indicates anuplink subframe, and S means the special subframe. Also, the above Table1 represents a downlink-uplink switching period of uplink/downlinksubframe configuration in each system.

In the following description, a carrier aggregation scheme is explained.FIG. 12 is a conceptual diagram for explaining a carrier aggregationscheme.

A carrier aggregation means a technology using one big logical frequencyband in a manner that a user equipment uses a frequency block configuredwith an uplink resource (or a component carrier) and/or a downlinkresource (or a component carrier) or a plurality of cells (of logicalmeaning) in order for a wireless communication system to use a widerfrequency band. For clarity, a terminology of ‘component carrier’ isconsistently used in the following description.

Referring to FIG. 7, a total system bandwidth (system BW) may have asystem bandwidth up to maximum 100 MHz as a logical bandwidth. The totalsystem bandwidth includes five component carriers and each of thecomponent carriers may have up to maximum 20 MHz. The component carrierincludes at least one physically contiguous subcarrier. Although each ofthe component carriers in FIG. 7 is depicted as including an identicalbandwidth, this is exemplary only. Each of the component carriers may beable to have a bandwidth different from each other. And, although eachof the component carriers is depicted as it is adjacent to each other infrequency domain, since the diagram is depicted in terms of a logicalconcept, each of the component carriers may be physically adjacent toeach other or may be apart from each other.

A center frequency can be differently used for each of the componentcarriers or a common center frequency can be used for the componentcarriers physically adjacent to each other. As an example, in FIG. 7, ifassumed that all component carriers are physically adjacent to eachother, a center frequency ‘A’ can be used. Or, if assumed that each ofthe component carriers is not physically adjacent to each other, such aseparate center frequency as a center frequency ‘A’, a center frequency‘B’ or the like can be used for each of the component carriers.

In the present specification, a component carrier may correspond to asystem bandwidth of a legacy system. By defining the component carrieron the basis of the legacy system, it may become easy to providebackward compatibility and to design a system in a radio communicationenvironment in which an evolved UE and a legacy UE coexist. As anexample, in case that LTE-A system supports a carrier aggregation, eachof the component carriers may correspond to a system bandwidth of LTEsystem. In this case, the component carrier may have a prescribedbandwidth among the bandwidths of 1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, or20 MHz.

In case that a total system bandwidth is expanded by a carrieraggregation, a frequency band used for communicating with each UE isdefined by a component carrier unit. A UE A may use 100 MHzcorresponding to the total system bandwidth and performs a communicationin a manner of using all of the five component carriers. A UE B₁˜B₅ canuse a bandwidth of 20 MHz only and performs a communication by using onecomponent carrier. A UE C₁ and a UE C₂ can use a bandwidth of 40 MHz andperforms a communication by using two component carriers, respectively.The two component carriers may or may not be logically/physicallyadjacent to each other. The UE C₁ indicates a case that the UE C₁ usestwo component carriers not adjacent to each other and the UE C₂indicates a case that the UE C₂ uses two component carriers adjacent toeach other.

LTE system uses one DL component carrier and one UL component carrier.On the other hand, LTE-A system may use a plurality of componentcarriers as depicted in FIG. 6. In this case, a scheme of scheduling adata channel, which is scheduled by a control channel, can be dividedinto a conventional linked carrier scheduling scheme and a cross carrierscheduling scheme.

More specifically, in case of the linked carrier scheduling scheme,similar to a legacy LTE system using a single component carrier, acontrol channel transmitted on a specific component carrier schedules adata channel only via the specific component carrier.

Meanwhile, in case of the cross carrier scheduling scheme, a controlchannel transmitted on a primary component carrier (primary CC)schedules a data channel transmitted on the primary component carrier ora different component carrier using a carrier indicator field(hereinafter abbreviated CIF).

In the following, a method for controlling uplink transmission power inan LTE system is explained.

A method for controlling, by a UE, uplink transmission power thereofincludes open loop power control (OLPC) and closed loop power control(CLPC). The former controls power in such a manner that attenuation of adownlink signal from a base station of a cell to which a UE belongs isestimated and compensated for. OLPC controls uplink power by increasinguplink transmission power when downlink signal attenuation increases asa distance between the UE and the base station increases. The lattercontrols uplink power in such a manner that the base station directlytransmits information (i.e. a control signal) necessary to controluplink transmission power.

The following equation 1 is used to determine transmission power of a UEwhen a serving cell c transmits only a PUSCH instead of simultaneouslytransmitting the PUSCH and a PUCCH in a subframe corresponding to asubframe index i in a system that supports carrier aggregation.

$\begin{matrix}{{P_{{PUSCH},c}(i)} = {\min {\begin{Bmatrix}{{P_{{CMAX},c}(i)},} \\{{10\mspace{11mu} {\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\; \_ \; {PUSCH}},c}(j)} +} \\{{{\alpha_{c}(j)} \cdot {PL}_{c}} + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}\mspace{11mu}\lbrack{dBm}\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

The following equation 2 is used to determine PUSCH transmission powerwhen the serving cell c simultaneously transmits the PUCCH and the PUSCHin the subframe corresponding to the subframe index i in a systemsupporting carrier aggregation.

$\begin{matrix}{{P_{{PUSCH},c}(i)} = {\min {\begin{Bmatrix}{{10\mspace{11mu} {\log_{10}\left( {{{\hat{P}}_{{CMAX},c}(i)} - {{\hat{P}}_{PUCCH}(i)}} \right)}},} \\{{10\mspace{11mu} {\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\; \_ \; {PUSCH}},c}(j)} +} \\{{{\alpha_{c}(j)} \cdot {PL}_{c}} + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{Bmatrix}\mspace{11mu}\lbrack{dBm}\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

Parameters, which will be described in association with Equations 1 and2, determine uplink transmission power of a UE in the serving cell c.Here, P_(CMAX,c)(i) in Equation 1 indicates maximum transmittable powerof the UE in the subframe corresponding to the subframe index i and{circumflex over (P)}_(CMAX,c)(i) in Equation 2 indicates a linear valueof P_(CMAX,c)(i). {circumflex over (P)}_(PUCCH)(i) in Equation 2indicates a linear value of P_(PUCCH)(i) (P_(PUCCH)(i) indicating PUCCHtransmission power in the subframe corresponding to subframe index i).

In Equation 1, M_(PUSCH,c)(i) is a parameter indicating a PUSCH resourceallocation bandwidth, which is represented as the number of resourceblocks valid for the subframe index i, and is allocated by a basestation. P_(O) _(_) _(PUSCH,c)(j) is a parameter corresponding to thesum of a cell-specific nominal component P_(O) _(_) _(NOMINAL) _(_)_(PUSCH,c)(j) provided by a higher layer and a UE-specific componentP_(O) _(_) _(UE) _(_) _(PUSCH,c)(j) provided by the higher layer and issignaled to the UE by the base station.

j is 1 in PUSCH transmission/retransmission according to an uplink grantand j is 2 in PUSCH transmission/retransmission according to a randomaccess response. In addition, P_(O) _(_) _(UE) _(_) _(PUSCH,c)(2)=0 andP_(O) _(_) _(NOMINAL) _(_) _(PUSCH,c)(2)=P_(O) _(_) _(PRE)+Δ_(PREAMBLE)_(_) _(Msg3). Parameters P_(O) _(_) _(PRE) and Δ_(PREAMBLE) _(_) _(Msg3)are signaled by the higher layer.

α_(c)(j) is a pathloss compensation factor and a cell-specific parameterprovided by the higher layer and transmitted as 3 bits by the basestation. αε{0, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1} when j is 0 or 1 andα_(c)(j)=1 when j is 2. α_(c)(j) is a value signaled to the UE by thebase station.

Δ_(TF)(i) indicates a value of a dynamic channel change compensated by amodulation and coding scheme (MCS) and is represented as Δ_(TF,c)(i)=10log₁₀((2^(BPRE·K) ^(s) −1)·β_(offset) ^(PUSCH)).

Pathloss PL_(c) is a downlink pathloss (or signal loss) estimate valuein dBs, calculated by the UE, and is represented asPL_(c)=referenceSignalPower−higher layer filteredRSRP. Here,referenceSignalPower can be signaled to the UE by the base station viathe higher layer.

δ_(PUSCH,c) is a correction value and is also referred to as a transmitpower command (TPC) command. The δ_(PUSCH,c) can be signaled to the UEin a manner of being included in PDCCH/EPDCCH of DCI format 0/4 of theservice cell c or in a manner of being joint coded with PDCCH of a DCIformat 3/3A including a CRC parity bit scrambled by TPC-PUSCH-RNTItogether with other TPC commands. If an accumulation mode is set to beactivated based on a parameter ‘Accumulation-Enabled’ provided by thehigher layer, or a TPC command included in PDCCH/EPDCCH of a DCI format0 of the serving cell c scrambled by a temporary C-RNTI is included, acurrent PUSCH power control adjustment state of the serving cell c isdefined as f_(c)(i)=f_(c)(i−1)+δ_(PUSCH,c)(i−K_(PUSCH)).

In particular, f_(c)(i) is a value indicating current PUSCH powercontrol adjustment state for the subframe index i and can be representedas a current absolute value or accumulated value. When accumulation isenabled on the basis of a parameter provided by the higher layer or aTPC command δ_(PUSCH,c) is included in a PDCCH along with DCI format 0for the serving cell c in which CRC is scrambled with temporary C-RNTI,f_(c)(i)=f_(c)(i−1)+δ_(PUSCH,c)(i−K_(PUSCH)) is satisfied.δ_(PUSCH,c)(i−K_(PUSCH)) is signaled through the PDCCH with DCI format0/4 or 3/3A in a subframe i−K_(PUSCH). Here, f_(c)(0) is the first valueafter reset of the accumulated value. If accumulation is not enabled onthe basis of the parameter provided by the higher layer,f_(c)(i)=δ_(PUSCH,c)(i−K_(PUSCH)) is satisfied. In this case,δ_(PUSCH,c)(i−K_(PUSCH)) is signaled by PDCCH/EPDCCH in a subframei−K_(PUSCH) together with DCI format 0/4.

K_(PUSCH) is defined in LTE as follows.

For FDD (Frequency Division Duplex), K_(PUSCH) has a value of 4. As toTDD, if TDD uplink/downlink configurations of at least two or moreconfigured serving cells are not identical to each other, “TDDuplink/downlink configuration” of the serving cell c may refer toUL-reference UL/DL configuration.

In TDD, if one or more serving cells are set to a UE and TDDuplink/downlink configurations of at least two or more configuredserving cells are not identical to each other, the TDD UL/DLconfiguration for the serving cell may refer to UL-reference UL/DLconfiguration.

In TDD, in case of UL/DL configuration 1 to 6, K_(PUSCH) has values asshown in Table 2.

TABLE 2 TDD UL/DL subframe number i Configuration 0 1 2 3 4 5 6 7 8 9 0— — 6 7 4 — — 6 7 4 1 — — 6 4 — — — 6 4 — 2 — — 4 — — — — 4 — — 3 — — 44 4 — — — — — 4 — — 4 4 — — — — — — 5 — — 4 — — — — — — — 6 — — 7 7 5 —— 7 7 —

In TDD, in case of UL/DL configuration 0, if PUSCH transmission isscheduled in a subframe 2 or 7 together with PDCCH/EPDCCH of a DCIformat 0/4 where an LSB of an uplink index is set to 1, K_(PUSCH) has avalue of 7 and K_(PUSCH) follows Table 2 for the rest of all PUSCHtransmissions.

The UE attempts to decode a PDCCH/EPDCCH in DCI format 0/4 with C-RNTIthereof, decode a PDCCH/EPDCCH in DCI format 0 with SPS C-RNTI or decodea PDCCH in DCI format 3/3A with TPC-PUSCH-RNTI thereof in each subframein cases other than deactivated state or DRX state of the serving cellc. When DCI formats 0/4 and 3/3A for the serving cell c are detected inthe same subframe, the UE needs to use δ_(PUSCH,c) provided in DCIformat 0/4. When a TPC command decoded for the serving cell c is notpresent, DRX is generated or a subframe having index i is a subframeother than an uplink subframe in TDD, δ_(PUSCH,c) is 0 dB.

Accumulated δ_(PUSCH,c), which is signaled together with DCI format 0/4on a PDCCH, is shown in Table 3. When a PDCCH/EPDCCH with DCI format 0is validated through SPS activation or released, δ_(PUSCH,c) is 0 dB.Accumulated δ_(PUSCH,c), which is signaled with DCI format 3/3A on aPDCCH, is one of SET1 of Table 3 or one of SET2 of Table 4, determinedby a TPC-index parameter provided by the higher layer.

TABLE 3 Absolute TPC Command Accumulated δ_(PUSCH,c) [dB] Field inδ_(PUSCH,c) only DCI DCI format 0/3/4 [dB] format 0/4 0 −1 −4 1 0 −1 2 11 3 3 4

TABLE 4 TPC Command Field in Accumulated δ_(PUSCH,c) DCI format 3A [dB]0 −1 1 1

When the UE reaches maximum transmission power {circumflex over(P)}_(CMAX)(i) in the serving cell c, a positive TPC command is notaccumulated for the serving cell c. Conversely, when the UE reachesminimum transmission power, a negative TPC command is not accumulated.

When P_(O) _(_) _(UE) _(_) _(PUSCH,c) value is changed by the higherlayer or a random access response message is received, the UE resetsaccumulation.

In this case, in case of an accumulative calculation type or a currentnon-accumulative (current absolute) calculation type, if the P_(O) _(_)_(UE) _(_) _(PUSCH,c) value is changed by the higher layer and theserving cell c corresponds to a primary cell or if the P_(O) _(_) _(UE)_(_) _(PUSCH,c) value is changed by the higher layer and the servingcell c corresponds to a secondary cell, an initial value of f_(c)(*) isall set/reset/initialized by f_(c)(0)=0.

Moreover, in LTE system, regarding uplink power of PUSCH, it may referto LTE/LTE-A standard document 3GPP TS 36.213 5.1.1 paragraph.

The following equation 3 is related to uplink power control with respectto a PUCCH in LTE.

$\begin{matrix}{{P_{PUCCH}(i)} = {\min {\begin{Bmatrix}{{P_{{CMAX},c}(i)},} \\{P_{0\_ \; {PUCCH}} + {PL}_{c} + {h\left( {n_{CQI},n_{HARQ},n_{SR}} \right)} +} \\{{\Delta_{F\; \_ \; {PUCCH}}(F)} + {\Delta_{TxD}\left( F^{\prime} \right)} + {g(i)}}\end{Bmatrix}\mspace{14mu}\lbrack{dBm}\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} 3} \right\rbrack\end{matrix}$

In Equation 3, i indicates a subframe index and c indicates a cellindex. When a UE is configured by a higher layer to transmit a PUCCHover through two antenna ports, Δ_(T×D)(F′) is provided to the UE by thehigher layer. In other cases, Δ_(T×D)(F′) is 0. Parameters with respectto a cell having the cell index c will now be described.

P_(CMAX,c)(i) indicates maximum transmission power of a UE, P₀ _(_)_(PUCCH) is a parameter corresponding to the sum of cell-specificparameters and signaled by a base station through higher layersignaling, PL_(c) is a downlink pathloss (or signal loss) estimate valuecalculated in dBs by the UE and is represented asPL_(c)=referenceSignalPower−higher layer filteredRSRP. h(n) a valuevarying depending on a PUCCH format, n_(CQI) is the number ofinformation bits with respect to channel quality information (CQI) andn_(HARQ) indicates the number of HARQ bits. In addition, Δ_(F) _(_)_(PUCCH)(F) is a relative value with respect to PUCCH format 1a and avalue corresponding to PUCCH format #F, which is signaled by the basestation through higher layer signaling. g(i) indicates a current PUCCHpower control adjustment state of a subframe having index i.

g(0)=0 when P_(O) _(_) _(UE) _(_) _(PUCCH) is changed in the higherlayer and g(0)=ΔP_(rampup)+δ_(msg2) otherwise. δ_(msg2) is a TPC commandindicated in a random access response and ΔP_(rampup) corresponds tototal power ramp-up from the first to last preambles, provided by thehigher layer.

When a UE reaches maximum transmission power P_(CMAX,c)(i) in a primarycell, a positive TPC command is not accumulated for the primary cell.When the UE reaches minimum transmission power, a negative TPC commandis not accumulated. The UE resets accumulation when P_(O) _(_) _(UE)_(_) _(PUCCH) is changed by the higher layer or upon reception of arandom access response.

Tables 5 and 6 show δ_(PUCCH) indicated by a TPC command in DCI formats.Particularly, Table 5 shows δ_(PUCCH) indicated in DCI formats otherthan DCI format 3A and Table 6 shows δ_(PUCCH) indicated in DCI format3A.

TABLE 5 TPC Command Field in DCI format δ_(PUSCH,c)1A/1B/1D/1/2A/2B/2C/2/3 [dB] 0 −1 1 0 2 1 3 3

TABLE 6 TPC Command Field in δ_(PUSCH,c) DCI format 3A [dB] 0 −1 1 1

Equation 4 in the following corresponds to an equation related to powercontrol of a sounding reference signal (SRS) in LTE system.

$\begin{matrix}{{P_{{SRS},c}(i)} = {\min {\begin{Bmatrix}{P_{{CMAX},c}(i)} \\\begin{matrix}{{P_{{{SRS}\; \_ \; {OFFSET}},c}(m)} + {10\mspace{11mu} {\log_{10}\left( M_{{SRS},c} \right)}} +} \\{{P_{{O\; \_ \; {PUSCH}},c}(j)} + {{\alpha_{c}(j)} \cdot {PL}_{c}} + {f_{c}(i)}}\end{matrix}\end{Bmatrix}\mspace{11mu}\lbrack{dBm}\rbrack}}} & \left\lbrack {{Equation}\mspace{14mu} 4} \right\rbrack\end{matrix}$

In Equation 4, i corresponds to a subframe index and c corresponds to acell index. In this case, P_(CMAX,c)(i) corresponds to maximum powercapable of being transmitted by a UE and P_(SRS) _(_) _(OFF) _(_)_(SET,c)(m) corresponds to a value configured by a higher layer. If m is0, it may correspond to a case of transmitting a periodic soundingreference signal. If m is not 0, it may correspond to a case oftransmitting an aperiodic sounding reference signal. M_(SRS,c)corresponds to a sounding reference signal bandwidth on a subframe indexi of a serving cell c and is represented by the number of resourceblocks.

f_(c)(i) corresponds to a value indicating a current PUSCH power controladjustment state for a subframe index i of a serving cell c. P_(O) _(_)_(PUSCH,c)(j) and α_(c)(j) are also identical to what is mentionedearlier in Equation 1 and 2.

Hereinafter, a Sounding Reference Signal (SRS) will be described.

A sounding reference signal (SRS) is composed of constant amplitude zeroauto correlation (CAZAC) sequences. SRSs transmitted from several UEsare CAZAC sequences (r^(SRS)(n)=r_(u,v) ^((α))(n)) having differentcyclic shift values (α) according to Equation 5 in the following.

$\begin{matrix}{\alpha = {2\pi \frac{n_{SRS}^{cs}}{8}}} & \left\lbrack {{Equation}\mspace{14mu} 5} \right\rbrack\end{matrix}$

In this case, n_(SRS) ^(cs) is a value set to each UE by a higher layerand has an integer value of 0 to 7. Accordingly, the cyclic shift valuemay have eight values according to n_(SRS) ^(cs).

CAZAC sequences generated from one CAZAC sequence through cyclic shifthave zero correlation values with sequences having different cyclicshift values. Using such property, SRSs of the same frequency domain maybe divided according to CAZAC sequence cyclic shift values. The SRS ofeach UE is allocated onto the frequency axis according to a parameterset by the eNB. The UE performs frequency hopping of the SRS so as totransmit the SRS with an overall uplink data transmission bandwidth.

Hereinafter, a detailed method of mapping physical resources fortransmitting SRSs in an LTE system will be described.

In order to satisfy transmit power P_(SRS) of a UE, an SRS sequencer^(SRS)(n) is first multiplied by an amplitude scaling factor β_(SRS)and is then mapped to a resource element (RE) having an index (k, l)from r^(SRS)(0) by Equation 6.

$\begin{matrix}{a_{{{2k} + k_{0}},l} = \left\{ \begin{matrix}{\beta_{SRS}{r^{SRS}(k)}} & {{k = 0},1,\ldots \mspace{14mu},{M_{{sc},b}^{RS} - 1}} \\0 & {otherwise}\end{matrix} \right.} & \left\lbrack {{Equation}\mspace{14mu} 6} \right\rbrack\end{matrix}$

In this case, k₀ denotes a frequency domain start point of an SRS and isdefined by Equation 7.

$\begin{matrix}{k_{0} = {k_{0}^{\prime} + {\sum\limits_{b = 0}^{B_{SRS}}\; {2M_{{sc},b}^{RS}n_{b}}}}} & \left\lbrack {{Equation}\mspace{14mu} 7} \right\rbrack\end{matrix}$

where, n_(b) denotes a frequency location index. k′₀ for a generaluplink subframe is defined by Equation 8 and k′₀ for an uplink pilottime is defined by Equation 9.

k ₀′=(└N _(RB) ^(UL)/2┘−m _(SRS,0)/2)N _(SC) ^(RB) +k _(TC)  [Equation8]

$\begin{matrix}{k_{0}^{\prime} = \left\{ \begin{matrix}{{\left( {N_{RB}^{UL} - m_{{SRS},0}^{\max}} \right)N_{sc}^{RB}} + k_{TC}} & {{{if}\mspace{14mu} \left( {{\left( {n_{f}\mspace{11mu} {mod}\mspace{11mu} 2} \right) \times \left( {2 - N_{SP}} \right)} + n_{hf}} \right){mod}\mspace{11mu} 2} = 0} \\k_{TC} & {otherwise}\end{matrix} \right.} & \left\lbrack {{Equation}\mspace{14mu} 9} \right\rbrack\end{matrix}$

In Equations 8 and 9, k_(TC) denotes a transmissionComb parametersignaled to a UE via a higher layer and has a value of 0 or 1. Inaddition, n_(hf) is 0 in an uplink pilot time slot of a first half frameand is 0 in an uplink pilot slot of a second half frame. M_(sc,b) ^(RS)is the length, that is, the bandwidth, if the SRS sequence expressed insubcarrier units defined by Equation 10.

M _(sc,b) ^(RS) =m _(SRS,b) N _(sc) ^(RB)/2  [Equation 10]

In Equation 10, m_(SRS,b) is a value signaled from an eNB according toan uplink bandwidth N_(RB) ^(UL).

The UE may perform frequency hopping of the SRS so as to transmit theSRS with the overall uplink data transmission bandwidth. Such frequencyhopping is set by a parameter b_(hop) having a value of 0 to 3 receivedfrom a higher layer.

If frequency hopping of the SRS is inactivated, that is, ifb_(hop)≧B_(SRS), a frequency location index n_(b) has a constant valueas shown in Equation 11. Here, n_(RRC) is a parameter received from ahigher layer.

n _(b)=└4n _(RRC) /m _(SRS,b)┘ mod N _(b)  [Equation 11]

Meanwhile, if frequency hopping of the SRS is activated, that is,b_(hop)<B_(SRS), a frequency location index n_(b) is defined byEquations 12 and 13.

$\begin{matrix}{\mspace{79mu} {n_{b} = \left\{ \begin{matrix}{\left\lfloor {4{n_{RRC}/m_{{SRS},b}}} \right\rfloor \mspace{11mu} {mod}\mspace{11mu} N_{b}} & {b \leq b_{hop}} \\{\left\{ {{F_{b}\left( n_{SRS} \right)} + \left\lfloor {4{n_{RRC}/m_{{SRS},b}}} \right\rfloor} \right\} \; {mod}\mspace{11mu} N_{b}} & {otherwise}\end{matrix} \right.}} & \left\lbrack {{Equation}\mspace{14mu} 12} \right\rbrack \\{{F_{b}\left( n_{SRS} \right)} = \left\{ \begin{matrix}{{\left( {N_{b}/2} \right)\left\lfloor \frac{n_{SRS}\mspace{11mu} {mod}\; {\prod\limits_{b^{\prime} = b_{hop}}^{b}\; N_{b^{\prime}}}}{\prod\limits_{b^{\prime} = b_{hop}}^{b - 1}\; N_{b^{\prime}}} \right\rfloor} + \left\lfloor \frac{n_{SRS}\; {mod}{\prod\limits_{b^{\prime} = b_{hop}}^{b}\; N_{b^{\prime}}}}{2{\prod\limits_{b^{\prime} = b_{hop}}^{b - 1}\; N_{b^{\prime}}}} \right\rfloor} & {{if}\mspace{14mu} N_{b}\mspace{14mu} {even}} \\{\left\lfloor {N_{b}/2} \right\rfloor \left\lfloor {n_{SRS}/{\prod\limits_{b^{\prime} = b_{hop}}^{b - 1}\; N_{b^{\prime}}}} \right\rfloor} & {{if}\mspace{14mu} N_{b}\mspace{14mu} {odd}}\end{matrix} \right.} & \left\lbrack {{Equation}\mspace{14mu} 13} \right\rbrack\end{matrix}$

where, n_(SRS) is a parameter used to calculate the number of times oftransmitting the SRS and is defined by Equation 14.

$\begin{matrix}{n_{SRS} = \left\{ \begin{matrix}{{{2N_{SP}n_{f}} + {2\left( {N_{SP} - 1} \right)\left\lfloor \frac{n_{s}}{10} \right\rfloor} + \left\lfloor \frac{T_{offset}}{T_{{offset}\; \_ \; \max}} \right\rfloor},} & {{for}\mspace{14mu} 2{ms}\mspace{11mu} {SRS}\mspace{14mu} {periodicity}\mspace{14mu} {of}\mspace{14mu} {TDD}\mspace{14mu} {frame}\mspace{14mu} {structure}} \\{\left\lfloor {\left( {{n_{f} \times 10} + \left\lfloor {n_{s}/2} \right\rfloor} \right)/T_{SRS}} \right\rfloor,} & {otherwise}\end{matrix} \right.} & \left\lbrack {{Equation}\mspace{14mu} 14} \right\rbrack\end{matrix}$

In Equation 14, T_(SRS) denotes the periodicity of an SRS and T_(offset)denotes a subframe offset of an SRS. In addition, n_(s) denotes a slotnumber and n_(f) denotes a frame number.

An SRS configuration index I_(SRS) for setting the periodicity T_(SRS)and the subframe offset T_(offset) of the SRS is shown in Table 7 toTable 10 according to FDD and TDD. In particular, Table 7 and Table 8indicate a FDD system and a TDD system, respectively. Table 7 and Table8 in the following show a period related to a triggering type 0, i.e., aperiodic SRS, and offset information.

TABLE 7 SRS Configuration SRS Periodicity SRS Subframe Offset IndexI_(SRS) T_(SRS) (ms) T_(offset) 0-1 2 I_(SRS) 2-6 5 I_(SRS)-2  7-16 10I_(SRS)-7 17-36 20 I_(SRS)-17 37-76 40 I_(SRS)-37  77-156 80 I_(SRS)-77157-316 160 I_(SRS)-157 317-636 320 I_(SRS)-317  637-1023 reservedreserved

TABLE 8 Configuration Index SRS Periodicity SRS Sub frame Offset I_(SRS)T_(SRS) (ms) T_(offset) 0 2 0, 1 1 2 0, 2 2 2 1, 2 3 2 0, 3 4 2 1, 3 5 20, 4 6 2 1, 4 7 2 2, 3 8 2 2, 4 9 2 3, 4 10-14 5 I_(SRS)-10 15-24 10I_(SRS)-15 25-44 20 I_(SRS)-25 45-84 40 I_(SRS)-45  85-164 80 I_(SRS)-85165-324 160 I_(SRS)-165 325-644 320 I_(SRS)-325  645-1023 reservedreserved

Table 9 and Table 10 in the following show a period related to atriggering type 1, i.e., an aperiodic SRS, and offset information. Inparticular, Table 9 and Table 10 indicate a FDD system and a TDD system,respectively.

TABLE 9 SRS SRS SRS Configuration Periodicity Subframe Index I_(SRS)T_(SRS,1) (ms) Offset T_(offset,1) 0-1  2 I_(SRS) 2-6  5 I_(SRS)-2  7-1610 I_(SRS)-7 17-31 reserved reserved

TABLE 10 SRS SRS SRS Configuration Periodicity Subframe Index I_(SRS)T_(SRS,1) (ms) Offset T_(offset,1) 0  2 0, 1 1  2 0, 2 2  2 1, 2 3  2 0,3 4  2 1, 3 5  2 0, 4 6  2 1, 4 7  2 2, 3 8  2 2, 4 9  2 3, 4 10-14  5I_(SRS)-10 15-24 10 I_(SRS)-15 25-31 reserved reserved

According to a recent wireless communication system, when an eNBperforms a duplex operation in a manner of dividing all availableresources into downlink resources and uplink resources, discussion on atechnology for more flexibly changing an operation of selecting a usageof each resource as a downlink resource or an uplink resource is inprogress.

The aforementioned method for flexibly changing usage of resources hasthe advantage that optimized resource distribution can be performed whensizes of DL traffic and UL traffic are flexibly varied. For example, Inoperations of an FDD system using frequency bands divided into a DL bandand a UL band, an eNB can designate a specific band to a DL resource ora UL resource at a specific time through an RRC, MAC or physical layersignal for flexible resource usage change.

In particular, a TDD system partitions all subframes into UL subframesand DL subframes and uses the UL subframes and DL subframes for ULtransmission of UEs and DL transmission of an eNB. Such UL/DLconfiguration is signaled to a UE as part of system information, ingeneral. Of course, it is able to additionally provide a new UL/DLsubframe configuration to a UE as well as the UL-DL subframeconfigurations shown in Table 1. For dynamic resource usage change inthe TDD system, the eNB can designate a specific subframe to a DLresource or a UL resource at a specific time through an RRC, MAC orphysical layer signal.

In legacy LTE systems, a DL resource and a UL resource are designatedthrough system information. Since the system information needs to betransmitted to a plurality of unspecified UEs, operations of legacy UEsmay have problems when the system information is dynamically changed.Accordingly, it is desirable to transmit information on dynamic resourceusage change to UEs currently linked to an eNB through new signaling,particularly, UE-specific signaling, rather than the system information.Such new signaling may indicate a configuration of a dynamically changedresource, for example, uplink/downlink subframe configurationinformation different from a configuration indicated through systeminformation in a TDD system.

In addition, such new signaling may include information related to HARQ.Particularly, the new signaling may include a scheduling message andPDSCH/PUSCH transmission timing corresponding thereto, and HARQ timelineconfiguration information for maintaining stable HARQ timeline even ifresource configuration is dynamically changed so as to solve a problemthat HARQ timeline, defined as HARQ-ACK transmission timeline, does notcontinue when the HARQ timeline is dynamically changed. In the case of aTDD system, the HARQ timeline configuration information can be providedas an uplink/downlink subframe configuration that is referred to whendownlink HARQ timeline and/or uplink HARQ timeline are defined.

As described above, a UE linked to a system that dynamically changesusage of resources receives various information about a resourceconfiguration. In particular, in case of a TDD system, a UE can acquirethe following information at a specific time.

1) UL/DL subframe configuration indicated by system information

2) UL/DL subframe configuration transmitted in order to indicate usageof each subframe through additional signaling

3) UL/DL configuration transmitted to define DL HARQ timeline, that is,when HARQ-ACK for a PDSCH received at a specific time will betransmitted

4) UL/DL subframe configuration transmitted to define UL HARQ timeline,that is, when a PUSCH for a UL grant received at a specific time will betransmitted and when a PHICH for a PUSCH transmitted at a specific timewill be received

When a specific UE is linked to an eNB that dynamically changes usage ofresources, the eNB may operate to set a UL/DL subframe configurationincluding as many UL SFs as possible through system information in manycases. This is because dynamic change of subframes, which are designatedas DL SFs through the system information, to UL SFs may be restricted.Specifically, since legacy UEs which cannot recognize dynamic resourceusage change expect and measure CRS transmission in subframes, which aredesignated as DL subframes through system information, all the time,serious error can be generated in CRS measurement of the legacy UEs whenthe DL subframes are dynamically changed to UL subframes. Accordingly,it is desirable that the eNB dynamically changes some UL SFs to DL SFswhen DL traffic increases while configuring a larger number of UL SFs onthe system information.

In a TDD system operating according to the aforementioned principle,although UL/DL configuration #0 is signaled to a UE through systeminformation at a specific time, usage of resources in each subframe mayconform to UL/DL subframe configuration #1.

In addition, DL HARQ timeline may be based on UL/DL subframeconfiguration #2. This is because HARQ timeline can be maintained evenif UL/DL subframe configurations are dynamically changed when HARQtimeline is based on a UL/DL subframe configuration including a smallernumber of UL SFs and a larger number of DL SFs such that the number ofDL SFs reaches a maximum number to cause a situation in which HARQ-ACKis difficult to transmit and DL HARQ timeline is operated in thissituation. Similarly, UL HARQ timeline may be based on a UL/DL subframeconfiguration including a larger number of UL SFs, such as UL/DLsubframe configuration #0.

Meanwhile, as mentioned in the foregoing description, UL transmissionpower control of a UE includes open loop power control (OLPC) and closedloop power control (CLPC). The former controls power in such a mannerthat attenuation of a downlink signal from an eNB (serving eNB, S-eNB)of a cell to which the UE belongs is estimated and compensated for. Forexample, OLPC controls uplink power by increasing uplink transmissionpower when downlink signal attenuation increases as a distance betweenthe UE and the eNB increases. The latter controls uplink power in such amanner that the eNB directly transmits information (i.e. a controlsignal) necessary for the eNB to control uplink transmission power.

However, these conventional uplink power control methods do not considera UE linked to an eNB that dynamically changes usage of resources. Whenthe conventional power control methods are used although specific ULtransmission is carried out in a UL SF to which dynamic resource usagechange is applied, UL transmission performance may be seriouslydeteriorated since interference environments are remarkably changed dueto DL transmission of a neighboring cell and the like.

Hence, a recent LTE system considers a method of designating a pluralityof subframe sets and applying different power control methods torespective subframe sets. Information on a plurality of the subframesets may be provided to UEs through higher layer signaling such as RRCsignaling, provided in associated with specific subframe set informationused for other purposes, or independently RRC-signaled.

For convenience of description, it is assumed that two subframe sets aresignaled. In this case, each of the two subframe sets is respectivelyreferred to as a subframe set #1 and a subframe set #2. The subframe set#1 and the subframe set #2 can be defined as L-bit subframe bitmaps. Inparticular, the subframe set #1 and the subframe set #2 may correspondto a static SF and a flexible SF, respectively.

FIG. 8 is a diagram for an example of dividing a radio frame into asubframe set #1 and a subframe set #2.

Referring to FIG. 8, a static subframe may correspond to legacy subframeto which a dynamic resource usage change is not applied. And, a flexiblesubframe may correspond to a subframe to which the dynamic resourceusage change is applied or capable of being applied. In particular,unlike the static subframe, since interference environment can beconsiderably changed in the flexible subframe when a UE performs uplinktransmission, it may be preferable to apply a separate power controlscheme to the flexible subframe.

In particular, referring to an example of FIG. 8, in a state that both acell A (serving cell) and a cell B (neighbor cell) configure anuplink/downlink subframe configuration #0 (i.e., DSUUUDSUUU) throughsystem information, the cell B changes a usage of #(n+3), #(n+4), #(n+8)and #(n+9) subframes into downlink subframes.

In this case, as shown in FIG. 8, the cell A sets a subframe set #1 anda subframe set #2 to UE(s) belonging to the cell A and may be able toapply a different power control scheme according to each subframe set.In particular, if inter-cell cooperation is available, neighbor cellsare able to appropriately configure subframe sets in consideration ofthe inter-cell cooperation when a specific cell applies a dynamicresource usage change. Or, if it is regulated as the prescribed subframeset configurations are applied only between cells in advance, thedynamic resource usage change can be applied to a specific subframe set(e.g., a subframe set #2 in FIG. 8) only.

Specifically, if legacy PUSCH PC in a specific subframe set (e.g., asubframe set #2 which is a flexible subframe) is applied to a differentspecific subframe set (e.g., a subframe set #1 which is a staticsubframe) as it is, performance degradation may occur due to a biginterference environment difference according to a subframe set. Hence,it is preferable to apply a PUSCH power control process which isseparated from each other according to each subframe set.

Based on the aforementioned contents, the present invention proposes amethod of efficiently controlling/managing transmission power of anuplink data information channel (PUSCH)/uplink control informationchannel (PUCCH) of a UE when a plurality of cells dynamically change ausage of a radio resource according to a system load state of the cells.

In the following, for clarity, the present invention is explained basedon 3GPP LTE system. However, a system range to which the presentinvention is applied can also be extended to a different system ratherthan the 3GPP LTE system.

Moreover, embodiments of the present invention can also be extensivelyapplied to a case that a resource on a specific cell or a componentcarrier (CC) is dynamically changed according to a load state of asystem under environment to which a carrier aggregation (CA) scheme isapplied.

And, the embodiments of the present invention can also be extensivelyapplied to a case that a usage of a radio resource is dynamicallychanged in a TDD system or a FDD system. In the following description,for clarity, assume a situation that each of the cells dynamicallychanges a usage of a legacy radio resource according to a system loadstate of the cell under TDD system environment.

According to the aforementioned contents, an open-loop parameter(open-loop control parameter) corresponds to P_(O) _(_) _(PUSCH,c)(j)and α_(c)(j) and a closed loop parameter (closed-loop control parameter)corresponds to f_(c)(i) and Δ_(TF,c)(i). And, as an example, it is ableto know that the power control of the legacy uplink data channel isdetermined by an accumulative calculation mode (accumulative TPCcommand) or a non-accumulative calculation mode (absolute TPC command)of a closed-loop parameter (i.e., f_(c)(i)) which is received accordingto “Accumulation-enabled” configuration (corresponding to a higher layersignal-related parameter).

In particular, when transmission power of an uplink data channel (PUSCH)transmitted at a specific subframe timing (i.e., SF #i) is determined,if the transmission power of the uplink data channel already reaches amaximum transmission power value (i.e., P_(CMAX,c)(i)) of a UE, a ruleis defined as closed-loop parameters (i.e., δ_(PUSCH,c)(i−K_(PUSCH)))(or TPC (Transmission Power Control) Commands) of a previously receivedpositive value as well as timing of receiving scheduling information (ULgrant) interlocked with uplink data channel transmission of the specificsubframe timing (i.e., SF #i) are not accumulatively calculated. As adifferent example, when transmission power of an uplink data channel(PUSCH) transmitted at a specific subframe timing (i.e., SF #i) isdetermined, if the transmission power of the uplink data channel alreadyreaches a minimum transmission power value of a UE, a rule is defined asclosed-loop parameters (i.e., δ_(PUSCH,c)(i−K_(PUSCH))) (or TPC(Transmission Power Control) Commands) of a previously received negativevalue as well as timing of receiving scheduling information (UL grant)interlocked with uplink data channel transmission of the specificsubframe timing (i.e., SF #i) are not accumulatively calculated.

Moreover, as mentioned in the foregoing description, dynamic powercontrol of an uplink data channel (PUSCH) is performed based on a TPCfield of a DCI format 0/4 or a TPC field of a DCI format 3/3A receivedat (predefined) subframe timings on which uplink scheduling information(UL grant) is received in TDD system.

When a neighbor cell dynamically changes a usage of a radio resource, adifferent type of interference is received in an uplink subframe ofrandom timing (i.e., SF #n) of a specific cell (e.g., serving cell)depending on a usage of a subframe used by the neighbor cell at thetiming.

For example, if the neighbor cell uses the subframe of the timing (i.e.,SF #n) in a manner of (re)changing a usage of the subframe into adownlink usage, downlink interference (hereinafter, I_DU) is received inan uplink subframe of the identical timing (i.e., SF #n) of the specificcell. In this case, the uplink subframe of the identical timing of thespecific cell has a relatively high IoT property. On the contrary, ifthe neighbor cell uses the subframe of the timing (i.e., SF #n) in amanner of (re)changing a usage of the subframe into an uplink usage,uplink interference (hereinafter, I_UU) is received in an uplinksubframe of the identical timing (i.e., SF #n) of the specific cell (inthis case, the uplink subframe of the identical timing of the specificcell has a relatively low IoT property).

Hence, the specific cell (e.g., serving cell) can configure“subframe-dependent uplink power control (hereinafter, SD_PC)” operationin consideration of subframe sets including a different interferencecharacteristic (i.e., I_DU, I_UU). In this case, the SD_PC includes i)an operation of configuring an independent (different) open-loop powercontrol parameter (OLPC) parameter (e.g., Po (i.e., A semi-static baselevel), α (i.e., An open-loop path-loss compensation component))according to a subframe set including a different interferencecharacteristic and/or ii) an operation of separating accumulation of aclosed-loop power control parameter (CLPC) Parameter (e.g., AccumulativeTPC command, Absolute TPC command, A component dependent on the MCS)according to a subframe set including a different interferencecharacteristic. Moreover, if the SD_PC operation is set, the specificcell can secure stable uplink communication or uplink communication ofidentical quality irrespective of uplink subframes of which interferencecharacteristic is different from each other.

A specific cell (serving cell) sets (signals) a subframe-dependentuplink power control mode (hereinafter, SD_PC mode) to a UE (serving UE)performing uplink communication with the specific cell. This is becauseinterference characteristics (i.e., I_DU, I_UU) different from eachother occur according to an uplink subframe set of the specific cellwhen a neighbor cell dynamically changes a usage of a radio resource. Inother word, in terms of the specific cell, whether to set (signal) theSD_PC mode may vary according to a change of external interference(e.g., whether or not a neighbor cell performing a dynamic change of aradio resource usage exists).

And, in terms of a UE, the number of uplink subframes to which anindependent uplink power control process (UL PC process) is applied mayvary according to whether or not the SD_PC mode is set (signaled) to theUE. In this case, if the SD_PC mode is not set, all uplink subframes areconsidered as a single set and a single UL PC process identical to alegacy process can be applied. On the contrary, if the SD_PC mode isset, maximum two uplink subframe sets exist according to uplink powercontrol subframe set (UL PC SF SET) configuration information signaledby a specific cell and an independent UL PC process can be appliedaccording to each uplink subframe set.

In the following, a method for a UE to which an SD_PC mode is set toefficiently reflect (inherit) an accumulation value of an uplinkcommunication-related closed-loop power control (CLPC) parameter (e.g.,f_(c)(i)) before the SD_PC mode is set (i.e., non-SD_PC mode) or amethod of efficiently reflecting (inheriting) an accumulation value of aprevious (i.e., in case of setting the number of uplink subframe setsto 1) uplink communication-related closed-loop power control (CLPC)parameter (e.g., f_(c)(i) when the number of uplink subframe sets ischanged (signaled) to 2 from 1 in a state that the SD_PC mode is set isexplained. In particular, when a serving cell c sets a parameter for twouplink subframe sets to a UE, a value of a PUSCH power controladjustment state is explained in the following.

In the following, for clarity, when the SD_PC mode is set or when thenumber of uplink subframe sets is set to 2 in the SD_PC mode, an uplinksubframe set including an interference characteristic of I_UU isreferred to as “SD_PC_SET0” (e.g., sort of static UL SF set) and anuplink subframe set including an interference characteristic of I_DU isreferred to as “SD_PC_SET1” (e.g., sort of flexible UL SF set).

And, the embodiments of the present invention described in the followingcan be configured to be restrictively applied only when accumulation ofa closed-loop power control parameter (e.g., f_(c)(i)) is separated fromeach other according to an uplink subframe set (e.g., SD_PC_SET0,SD_PC_SET1), which is formed due to the SD_PC mode or due to theconfiguration of the number of uplink subframe sets configured by two inthe SD_PC mode. Moreover, a state of which the SD_PC mode is not set mayoperate in a manner of being identical to a case of designating oneuplink subframe set only in a state that the SD_PC mode is set in termsof an uplink power control operation. Hence, the embodiments of thepresent invention described in the following can also be extensivelyapplied to i) a case that the number of uplink subframe sets is changedto 2 from 1 and ii) a case that the number of uplink subframe sets issignaled to 2 from 1 in the state that the SD_PC mode is set.

Embodiment 1

According to embodiment 1 of the present invention, before the SD_PCmode is set or when the number of uplink subframes is set to 1 in theSD_PC mode, an accumulation value of an uplink communication-relatedclosed-loop power control parameter (e.g., F_(c)(i)) can be configurednot to be reflected (inherited) to SD_PC_SET0 and SD_PC_SET1, which areformed due to configuration of the SD_PC mode or due to the change ofthe number of uplink subframe sets, which is changed to 2 in the SD_PCmode.

In particular, according to the embodiment 1 of the present invention,before the SD_PC mode is set, the accumulation value of the uplinkcommunication-related closed-loop power control parameter (e.g.,f_(c)(i)) can be initialized or reset. And, when the number of uplinksubframes is set to 1 in the SD_PC mode, if the number of uplinksubframe sets is changed to 2 in the SD_PC mode, the accumulation valueof the uplink communication-related closed-loop power control parametercan be initialized or reset.

Embodiment 2

According to embodiment 2 of the present invention, before the SD_PCmode is set or when the number of uplink subframes is set to 1 in theSD_PC mode, an accumulation value of an uplink communication-relatedclosed-loop power control parameter (e.g., F_(c)(i)) can be configuredto be reflected (inherited) to SD_PC_SET0 (i.e., uplink subframe sethaving an interference characteristic of I-UU) only, which is formed dueto configuration of the SD_PC mode or due to the change of the number ofuplink subframe sets, which is changed to 2 in the SD_PC mode.

In particular, in terms of SD_PC_SET1 (i.e., uplink subframe set havingan interference characteristic of I-DU), which is formed due toconfiguration of the SD_PC mode or due to the change of the number ofuplink subframe sets which is changed to 2 in the SD_PC mode, before theSD_PC mode is set or when the number of uplink subframes is set to 1 inthe SD_PC mode, the accumulation value of the uplinkcommunication-related closed-loop power control parameter (e.g.,f_(c)(i)) can be initialized or reset (e.g., 0) due to the SD_PC modeconfiguration or due to the change of the number of uplink subframesets, which is changed to 2 in the SD_PC mode.

Moreover, before the SD_PC mode is set or when the number of uplinksubframes is set to 1 in the SD_PC mode, if the accumulation value ofthe uplink communication-related closed-loop power control parameter isreflected (inherited) to the SD_PC_set0, which is formed due toconfiguration of the SD_PC mode or due to the change of the number ofuplink subframe sets which is changed to 2 in the SD_PC mode, it is ableto configure a result value by which a predefined (signaled) weight ismultiplied to be reflected (or inherited) to the SD_PC_SET0.

As a different example, before the SD_PC mode is set or when the numberof uplink subframes is set to 1 in the SD_PC mode, an accumulation valueof an uplink communication-related closed-loop power control parameter(e.g., F_(c)(i)) can be configured to be reflected (inherited) toSD_PC_SET1 (i.e., uplink subframe set having an interferencecharacteristic of I-DU) only, which is formed due to configuration ofthe SD_PC mode or due to the change of the number of uplink subframesets, which is changed to 2 in the SD_PC mode.

Moreover, before the SD_PC mode is set or when the number of uplinksubframes is set to 1 in the SD_PC mode, if the accumulation value ofthe uplink communication-related closed-loop power control parameter isreflected (inherited) to the SD_PC_SET1, which is formed due toconfiguration of the SD_PC mode or due to the change of the number ofuplink subframe sets which is changed to 2 in the SD_PC mode, it is ableto configure a result value by which a predefined (signaled) weight ismultiplied to be reflected (or inherited) to the SD_PC_SET1.

Embodiment 3

According to embodiment 3 of the present invention, before the SD_PCmode is set or when the number of uplink subframes is set to 1 in theSD_PC mode, an accumulation value of an uplink communication-relatedclosed-loop power control parameter (e.g., F_(c)(i)) can be configuredto be reflected (inherited) to both SD_PC_SET0 and SD_PC_SET1, which areformed due to configuration of the SD_PC mode or due to the change ofthe number of uplink subframe sets, which is changed to 2 in the SD_PCmode.

In this case, before the SD_PC mode is set or when the number of uplinksubframes is set to 1 in the SD_PC mode, if the accumulation value ofthe uplink communication-related closed-loop power control parameter isreflected (inherited) to both the SD_PC_SET0 and the SD_PC_SET1, whichare formed due to configuration of the SD_PC mode or due to the changeof the number of uplink subframe sets which is changed to 2 in the SD_PCmode, it is able to configure result values by which i) predefined(signaled) weights different from each other or ii) predefined weightsidentical to each other are multiplied to be reflected (or inherited)according to an uplink subframe set (i.e., SD_PC_SET0, SD_PC_SET1)including a different interference characteristic.

Embodiment 4

According to embodiment 4 of the present invention, before the SD_PCmode is set or when the number of uplink subframes is set to 1 in theSD_PC mode, an accumulation value of an uplink communication-relatedclosed-loop power control parameter (e.g., F_(c)(i)) can be configuredto be restrictively reflected (inherited) to SD_PC_SET0 (i.e., uplinksubframe set having an interference characteristic of I-UU) only, whichis formed due to configuration of the SD_PC mode or due to the change ofthe number of uplink subframe sets which is changed to 2 in the SD_PCmode, only when a part (or all) of open-loop (OLCP) parameters (e.g.,P_(O) _(_) _(UE) _(_) _(PUSCH,c), P_(O) _(_) _(NOMINAL) _(_) _(PUSCH,c),α_(c)) related to the SD_PC_SET0 is identically maintained with valuesof before the SD_PC mode is set or values of when the number of uplinksubframes is set to 1 in the SD_PC mode.

As a different example, before the SD_PC mode is set or when the numberof uplink subframes is set to 1 in the SD_PC mode), an accumulationvalue of an uplink communication-related closed-loop power controlparameter (e.g., F_(c)(i)) can be configured to be restrictivelyreflected (inherited) to SD_PC_SET1 (i.e., uplink subframe set having aninterference characteristic of I-DU) only, which is formed due toconfiguration of the SD_PC mode or due to the change of the number ofuplink subframe sets which is changed to 2 in the SD_PC mode, only whena part (or all) of open-loop (OLCP) parameters (e.g., P_(O) _(_) _(UE)_(_) _(PUSCH,c), P_(O) _(_) _(NOMINAL) _(_) _(PUSCH,c), α_(c)) relatedto the SD_PC_SET1 is identically maintained with values of before theSD_PC mode is set or values of when the number of uplink subframes isset to 1 in the SD_PC mode.

Embodiment 5

According to embodiment 5 of the present invention, before the SD_PCmode is set (or when the number of uplink subframes is set to 1 in theSD_PC mode), an accumulation value of an uplink communication-relatedclosed-loop power control parameter (e.g., F_(c)(i)) can be configuredto be reflected (inherited) to an uplink subframe set having a lowest ora relatively low subframe set index (e.g., 0) only among uplink subframesets of which interference characteristic is different from each other,which are formed due to configuration of the SD_PC mode or due to thechange of the number of uplink subframe sets which is changed to 2 inthe SD_PC mode. In this case, as an example, it is able to configure alowest subframe set index (e.g., 0) to be assigned to an uplink subframeset having an interference characteristic of I_UU or an uplink subframeset having an interference characteristic of I_DU.

As a different example, before the SD_PC mode is set or when the numberof uplink subframes is set to 1 in the SD_PC mode, an accumulation valueof an uplink communication-related closed-loop power control parameter(e.g., F_(c)(i)) can be configured to be reflected (inherited) to anuplink subframe set having a highest or a relatively high subframe setindex (e.g., 1) only among uplink subframe sets of which interferencecharacteristic is different from each other, which are formed due toconfiguration of the SD_PC mode or due to the change of the number ofuplink subframe sets which is changed to 2 in the SD_PC mode. In thiscase, as an example, it is able to configure a highest subframe setindex (e.g., 1) to be assigned to an uplink subframe set having aninterference characteristic of I_UU or an uplink subframe set having aninterference characteristic of I_DU.

Embodiment 6

According to embodiment 6 of the present invention, before the SD_PCmode is set or when the number of uplink subframes is set to 1 in theSD_PC mode, it is able to configure a base station (or a cell) to inform(signal) a UE of i) an uplink subframe set index or ii) a UL PC processindex (i.e., a specific UL PC process index is interlocked with aspecific uplink subframe set index) to which an accumulation value of anuplink communication-related closed-loop power control parameter (e.g.,F_(c)(0) is inherited (reflected).

In this case, it is able to configure the information according to theembodiment 6 of the present invention to be transmitted in a manner ofbeing included in a usage change message (reconfiguration message)(transmitted based on a predetermined period) or it is able to configurethe information to be transmitted via a predefined (additional) signal(e.g., a higher layer signal or a physical layer signal).

A proposed scheme described in the following corresponds to a method ofefficiently reflecting (inheriting) an accumulation value of a specificuplink subframe set (e.g., SD_PC_SET1 and/or SD_PC_SET2)-relatedclosed-loop power control (CLPC) parameter (e.g., f_(SD) _(_) _(PC) _(_)_(SET0,c)(i), f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) when a UE to which anSD_PC mode is set is disabled from the SD_PC mode or a method ofefficiently reflecting (inheriting) an accumulation value of a specificuplink subframe set (e.g., SD_PC_SET1 and/or SD_PC_SET2)-relatedclosed-loop power control (CLPC) parameter (e.g., f_(SD) _(_) _(PC) _(_)_(SET0,c)(i), f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) of which the numberof uplink subframe sets is set to 2 when the number of uplink subframesets is changed (signaled) to 1 from 2 in a state that the SD_PC mode isset.

And, embodiments described in the following can be configured to berestrictively applied only when accumulation of a closed-loop powercontrol parameter (e.g., f_(c)(i)) is separated according to an uplinksubframe set (e.g., SD_PC_SET0, SD_PC_SET1) which is formed due to SD_PCmode configuration or due to the configuration of the uplink subframesets set to 2 in the SD_PC mode. Moreover, if the SD_PC mode isdisabled, it can be considered as being identical to a case of changing(signaling) the number of uplink subframe sets into 1 from 2 in terms ofan uplink power control operation in a state that the SD_PC mode is set.Hence, the embodiments of the present invention described in thefollowing can be extensively applied to i) a case that the number ofuplink subframe sets is changed to 1 from 2 or ii) a case that thenumber of uplink subframe sets is signaled to 1 from 2 when the SD_PCmode is set.

Embodiment 7

According to embodiment 7 of the present invention, it is able toconfigure all accumulation values of a closed-loop power controlparameter (e.g., f_(SD) _(_) _(PC) _(_) _(SET0,c)(i), f_(SD) _(_) _(PC)_(_) _(SET1,c)(i)) related to SD_PC_SET0 and SD_PC_SET1, which areformed due to SD_PC mode configuration or due to the configuration ofthe number of uplink subframe sets set to 2 in the SD_PC mode, not to bereflected (inherited).

In particular, according to the embodiment 7 of the present invention,the accumulation values of the closed-loop power control parameter(e.g., f_(SD) _(_) _(PC) _(_) _(SET0,c)(i), f_(SD) _(_) _(PC) _(_)_(SET1,c)(i)) related to the SD_PC_SET0 and the SD_PC_SET1, which areformed due to the SD_PC mode configuration or due to the configurationof the number of uplink subframe sets set to 2 in the SD_PC mode, can beinitialized or reset by disabling the SD_PC mode or can be initializedor reset by changing the number of uplink subframe sets to 1 in theSD_PC mode.

Embodiment 8

According to embodiment 8 of the present invention, it is able toconfigure an accumulation value of a closed-loop power control parameter(e.g., f_(SD) _(_) _(PC) _(_) _(SET0,c)(i)) related to SD_PC_SET0, whichis formed due to SD_PC mode configuration or due to the configuration ofthe number of uplink subframe sets set to 2 in the SD_PC mode, to bereflected (inherited) only.

In particular, the accumulation value of the closed-loop power controlparameter (e.g., f_(SD) _(_) _(PC) _(_) _(SET0,c)(i)) related to theSD_PC_SET1, which is formed due to the SD_PC mode configuration or dueto the configuration of the number of uplink subframe sets set to 2 inthe SD_PC mode, can be initialized or reset by disabling the SD_PC modeor can be initialized or reset by changing the number of uplink subframesets to 1 in the SD_PC mode. Moreover, when an accumulation value of aclosed-loop power control parameter (e.g., f_(SD) _(_) _(PC) _(_)_(SET0,c)(i)) related to SD_PC_SET0, which is formed due to SD_PC modeconfiguration or due to the configuration of the number of uplinksubframe sets set to 2 in the SD_PC mode, is reflected (inherited) only,it is able to configure a result value by which a predefined (signaled)weight is multiplied to be reflected (inherited).

As a different example, it is able to configure an accumulation value ofa closed-loop power control parameter (e.g., f_(SD) _(_) _(PC) _(_)_(SET1,c)(i)) related to SD_PC_SET1, which is formed due to SD_PC modeconfiguration or due to the configuration of the number of uplinksubframe sets set to 2 in the SD_PC mode, to be reflected (inherited)only. Moreover, when the accumulation value of the closed-loop powercontrol parameter (e.g., f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) related toSD_PC_SET1, which is formed due to SD_PC mode configuration or due tothe configuration of the number of uplink subframe sets set to 2 in theSD_PC mode, is reflected (inherited) only, it is able to configure aresult value by which a predefined (signaled) weight is multiplied to bereflected (inherited).

Embodiment 9

According to embodiment 9 of the present invention, it is able toconfigure accumulation values of a closed-loop power control parameter(e.g., f_(SD) _(_) _(PC) _(_) _(SET0,c)(i), f_(SD) _(_) _(PC) _(_)_(SET1,c)(i)) related to SD_PC_SET0 and SD_PC_SET1, which are formed dueto SD_PC mode configuration or due to the configuration of the number ofuplink subframe sets set to 2 in the SD_PC mode, to be proportionallyreflected (inherited) based on a predefined configuration/rule/function.

In this case, it is able to configure i) anarithmetic/geometric/weighted average value, ii) a minimum value, oriii) a maximum value of the accumulation values of the closed-loop powercontrol parameter (e.g., f_(SD) _(_) _(PC) _(_) _(SET0,c)(i), f_(SD)_(_) _(PC) _(_) _(SET1,c)(i)) related to the SD_PC_SET0 and theSD_PC_SET1, which are formed due to the SD_PC mode configuration or dueto the configuration of the number of uplink subframe sets set to 2 inthe SD_PC mode, to be reflected (inherited).

Embodiment 10

According to embodiment 10 of the present invention, it is able toconfigure a maximum value to be reflected (or inherited) amongaccumulation values of a closed-loop power control parameter (e.g.,f_(SD) _(_) _(PC) _(_) _(SET0,c)(i), f_(SD) _(_) _(PC) _(_)_(SET1,c)(i)) related to SD_PC_SET0 and SD_PC_SET1, which are formed dueto SD_PC mode configuration or due to the configuration of the number ofuplink subframe sets set to 2 in the SD_PC mode. Or, it is able toconfigure a minimum value to be reflected (or inherited) amongaccumulation values of a closed-loop power control parameter (e.g.,f_(SD) _(_) _(PC) _(_) _(SET0,c)(i), f_(SD) _(_) _(PC) _(_)_(SET1,c)(i)) related to SD_PC_SET0 and SD_PC_SET1, which are formed dueto SD_PC mode configuration or due to the configuration of the number ofuplink subframe sets set to 2 in the SD_PC mode.

Embodiment 11

According to embodiment 11 of the present invention, it is able toconfigure an operation of reflecting (inheriting) an accumulation valueof a closed-loop power control parameter (e.g., f_(SD) _(_) _(PC) _(_)_(SET0,c)(i)) related to SD_PC_SET0, which is formed due to SD_PC modeconfiguration or due to the configuration of the number of uplinksubframe sets set to 2 in the SD_PC mode, to be restrictively applied toa case that open-loop parameters are configured (maintained) by a valueidentical to a part (or all) of open-loop (OLPC) parameters (e.g., P_(O)_(_) _(UE) _(_) _(PUSCH,c), P_(O) _(_) _(NOMINAL) _(_) _(PUSCH,c),α_(c)) related to the SD_PC_SET0 after the SD_PC mode is disabled or thenumber of uplink subframe sets is changed into 1 in the SD_PC mode).

Or, it is able to configure an operation of reflecting (inheriting) anaccumulation value of a closed-loop power control parameter (e.g.,f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) related to SD_PC_SET1, which isformed due to SD_PC mode configuration or due to the configuration ofthe number of uplink subframe sets set to 2 in the SD_PC mode, to berestrictively applied to a case that open-loop parameters are configured(maintained) by a value identical to a part (or all) of open-loop (OLPC)parameters (e.g., P_(O) _(_) _(UE) _(_) _(PUSCH,c), P_(O) _(_)_(NOMINAL) _(_) _(PUSCH,c), α_(c)) related to the SD_PC_SET1 after theSD_PC mode is disabled or the number of uplink subframe set is changedinto 1 in the SD_PC mode.

Embodiment 12

According to embodiment 12 of the present invention, it is able toconfigure an accumulation value of an uplink subframe set-relatedclosed-loop power control parameter (e.g., f_(SD) _(_) _(PC) _(_)_(SET0,c)(i), f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) having a lowest orrelatively low subframe set index (e.g., 0) to be reflected (inherited)only among uplink subframe sets of which interference characteristic isdifferent from each other, which are formed due to SD_PC modeconfiguration or due to the configuration of the number of uplinksubframe sets set to 2 in the SD_PC mode. For example, it is able toconfigure a lowest subframe set index (e.g., 0) to be assigned to anuplink subframe set having interference characteristic of I_UU or it isable to configure a lowest subframe set index (e.g., 0) to be assignedto an uplink subframe set having interference characteristic of I_DU.

Or, it is able to configure an accumulation value of an uplink subframeset-related closed-loop power control parameter (e.g., f_(SD) _(_) _(PC)_(_) _(SET0,c)(i), f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) having a highest(or relatively high) subframe set index (e.g., 1) to be reflected(inherited) only among uplink subframe sets of which interferencecharacteristic is different from each other, which are formed due toSD_PC mode configuration or due to the configuration of the number ofuplink subframe sets set to 2 in the SD_PC mode. In this case, as anexample, it is able to configure a highest subframe set index (e.g., 1)to be assigned to an uplink subframe set having interferencecharacteristic of I_UU or it is able to configure a highest subframe setindex (e.g., 1) to be assigned to an uplink subframe set havinginterference characteristic of I_DU.

Embodiment 13

According to embodiment 13 of the present invention, among accumulationvalues of a closed-loop power control parameter (e.g., f_(SD) _(_) _(PC)_(_) _(SET0,c)(i), f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) related toSD_PC_SET0 and SD_PC_SET1, which are formed due to SD_PC modeconfiguration or due to the configuration of the number of uplinksubframe sets set to 2 in the SD_PC mode, it is able to configure a basestation (or a cell) to inform (signal) a UE of i) an uplink subframe setindex or ii) a UL PC process index (i.e., a specific UL PC process indexis interlocked with a specific uplink subframe set index) to which anaccumulation value of an uplink communication-related closed-loop powercontrol parameter (e.g., F_(c)(i)) is inherited (reflected).

In this case, it is able to configure the information according to thepresent embodiment to be transmitted in a manner of being included in ausage change message (reconfiguration message) (transmitted based on apredetermined period) or it is able to configure the information to betransmitted via a predefined (additional) signal (e.g., a higher layersignal or a physical layer signal).

A proposed scheme described in the following corresponds to a method ofefficiently reflecting (inheriting) an accumulation value of closed-looppower control parameters (e.g., f_(SD) _(_) _(PC) _(_) _(SET0,c)(i),f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) related to a specific uplinksubframe set (e.g., SD_PC_SET1 and/or SD_PC_SET2) when separateaccumulation of a closed-loop power control (CLPC) parameter (e.g.,f_(c)(i)) according to a subframe set (e.g., SD_PC_SET0, SD_PC_SET1) isdisabled (i.e., uplink subframe sets different from each other assumeaccumulation of a common closed-loop power control (CLPC) parameter(e.g., assume accumulation of f_(c)(i)) in a state that the SD_PC modeis set.

In the following, for clarity, when separate accumulation of aclosed-loop power control (CLPC) parameter according to a subframe setis disabled, it is referred to as “SEPARATE_ACCUMULATION-DISABLE”. And,when separate accumulation of a closed-loop power control (CLPC)parameter according to a subframe set is enabled, it is referred to as“SEPARATE_ACCUMULATION-ENABLE”.

Embodiment 14

According to embodiment 14 of the present invention, it is able toconfigure all accumulation values of closed-loop power controlparameters (e.g., f_(SD) _(_) _(PC) _(_) _(SET0,c)(i), f_(SD) _(_) _(PC)_(_) _(SET1,c)(i)) related to SD_PC_SET0 and SD_PC_SET1 not to bereflected (or inherited). In particular, the accumulation values of theclosed-loop power control parameters (e.g., f_(SD) _(_) _(PC) _(_)_(SET0,c)(i), f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) related to theSD_PC_SET0 and the SD_PC_SET1 can be initialized or reset due toSEPARATE_ACCUMULATION-DISABLE.

Embodiment 15

According to embodiment 15 of the present invention, it is able toconfigure an accumulation value of closed-loop power control parameter(e.g., f_(SD) _(_) _(PC) _(_) _(SET0,c)(i)) related to SD_PC_SET0 to bereflected (or inherited) only. In particular, in terms of SD_PC_SET1(i.e., an uplink subframe set having interference characteristic ofI_DU), an accumulation value of closed-loop power control parameter(e.g., f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) related to the SD_PC_SET1can be initialized or reset due to SEPARATE_ACCUMULATION-DISABLE.Moreover, if the accumulation value of the closed-loop power controlparameter (e.g., f_(SD) _(_) _(PC) _(_) _(SET0,c)(i)) related to theSD_PC_SET0 is reflected (inherited) only, it is able to configure aresult value by which a predefined (signaled) weight is multiplied to bereflected (inherited).

Or, It is able to configure the accumulation value of the closed-looppower control parameter (e.g., f_(SD) _(_) _(PC) _(_) _(SET1,c)(i))related to the SD_PC_SET1 to be reflected (or inherited) only. In thiscase, if the accumulation value of the closed-loop power controlparameter (e.g., f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) related to theSD_PC_SET1 is reflected (inherited) only, it is able to configure aresult value by which a predefined (signaled) weight is multiplied to bereflected (inherited).

Embodiment 16

According to embodiment 16 of the present invention, it is able toconfigure accumulation values of closed-loop power control parameters(e.g., f_(SD) _(_) _(PC) _(_) _(SET0,c)(i), f_(SD) _(_) _(PC) _(_)_(SET1,c)(i)) related to SD_PC_SET0 and SD_PC_SET1 to be proportionallyreflected (inherited) based on a predefined configuration/rule/function.For example, it is able to configure i) an arithmetic/geometric/weightedaverage value, ii) a minimum value or iii) a maximum value of theaccumulation values of the closed-loop power control parameter (e.g.,f_(SD) _(_) _(PC) _(_) _(SET0,c)(i), f_(SD) _(_) _(PC) _(_)_(SET1,c)(i)) related to the SD_PC_SET0 and the SD_PC_SET1 to bereflected (inherited).

Embodiment 17

According to embodiment 17 of the present invention, it is able toconfigure a maximum value to be reflected (or inherited) amongaccumulation values of a closed-loop power control parameter (e.g.,f_(SD) _(_) _(PC) _(_) _(SET0,c)(i), f_(SD) _(_) _(PC) _(_)_(SET1,c)(i)) related to SD_PC_SET0 and SD_PC_SET1. Or, it is able toconfigure a minimum value to be reflected (or inherited) amongaccumulation values of a closed-loop power control parameter (e.g.,f_(SD) _(_) _(PC) _(_) _(SET0,c)(i), f_(SD) _(_) _(PC) _(_)_(SET1,c)(i)) related to SD_PC_SET0 and SD_PC_SET1.

Embodiment 18

According to embodiment 18 of the present invention, it is able toconfigure an operation of reflecting (inheriting) an accumulation valueof a closed-loop power control parameter (e.g., f_(SD) _(_) _(PC) _(_)_(SET0,c)(i)) related to SD_PC_SET0 to be restrictively applied to acase that a part (or all) of open-loop (OLPC) parameters (e.g., P_(O)_(_) _(UE) _(_) _(PUSCH,c), P_(O) _(_) _(NOMINAL) _(_) _(PUSCH,c),α_(c)) related to the SD_PC_SET0 are identically maintained withprevious (i.e., SEPARATE_ACCUMULATION-ENABLE) values or a case that apart (or all) of open-loop (OLPC) parameters related to the SD_PC_SET0and the SD_PC_SET1 are identically maintained with previous (i.e.,SEPARATE_ACCUMULATION-ENABLE) values only afterSEPARATE_ACCUMULATION-DISABLE.

As a different example, it is able to configure an operation ofreflecting (inheriting) an accumulation value of a closed-loop powercontrol parameter (e.g., f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) related toSD_PC_SET1 to be restrictively applied to a case that a part (or all) ofopen-loop (OLPC) parameters (e.g., P_(O) _(_) _(UE) _(_) _(PUSCH,c),P_(O) _(_) _(NOMINAL) _(_) _(PUSCH,c), α_(c)) related to the SD_PC_SET1are identically maintained with previous (i.e.,SEPARATE_ACCUMULATION-ENABLE) values or a case that a part (or all) ofopen-loop (OLPC) parameters related to the SD_PC_SET0 and the SD_PC_SET1are identically maintained with previous (i.e.,SEPARATE_ACCUMULATION-ENABLE) values) only afterSEPARATE_ACCUMULATION-DISABLE.

Embodiment 19

According to embodiment 19 of the present invention, it is able toconfigure an accumulation value of an uplink subframe set-relatedclosed-loop power control parameter (e.g., f_(SD) _(_) _(PC) _(_)_(SET0,c)(i), f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) having a lowest or arelatively low subframe set index (e.g., 0) to be reflected (inherited)only among uplink subframe sets of which interference characteristic isdifferent from each other. For example, it is able to configure a lowestsubframe set index (e.g., 0) to be assigned to an uplink subframe sethaving interference characteristic of I_UU or an uplink subframe sethaving interference characteristic of I_DU.

Or, it is able to configure an accumulation value of an uplink subframeset-related closed-loop power control parameter (e.g., f_(SD) _(_) _(PC)_(_) _(SET0,c)(i), f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) having a highestor a relatively high subframe set index (e.g., 1) to be reflected(inherited) only among uplink subframe sets of which interferencecharacteristic is different from each other. For example, it is able toconfigure a highest subframe set index (e.g., 1) to be assigned to anuplink subframe set having interference characteristic of I_UU or anuplink subframe set having interference characteristic of I_DU.

Embodiment 20

According to embodiment 20 of the present invention, among accumulationvalues of a closed-loop power control parameter (e.g., f_(SD) _(_) _(PC)_(_) _(SET0,c)(i), f_(SD) _(_) _(PC) _(_) _(SET1,c)(i)) related toSD_PC_SET0 and SD_PC_SET1, it is able to configure a base station (or acell) to inform (signal) a UE of i) an uplink subframe set index or ii)a UL PC process index (i.e., a specific UL PC process index isinterlocked with a specific uplink subframe set index) to which anaccumulation value is inherited (reflected). In this case, it is able toconfigure the information to be transmitted in a manner of beingincluded in a usage change message (reconfiguration message)(transmitted based on a predetermined period) or it is able to configurethe information to be transmitted via a predefined (additional) signal(e.g., a higher layer signal or a physical layer signal.

In the following, a method of efficiently reflecting (inheriting) anaccumulation value of uplink communication-related closed-loop powercontrol (CLPC) parameter (e.g., f_(c)(i)) inSEPARATE_ACCUMULATION-DISABLE operation according to the presentinvention is explained when SEPARATE_ACCUMULATION-DISABLE is changedinto SEPARATE_ACCUMULATION-ENABLE in a state that SD_PC mode is set.

Embodiment 21

According to embodiment 21 of the present invention, it is able toconfigure an accumulation value of uplink communication-relatedclosed-loop power control (CLPC) parameter (e.g., f_(c)(i)) not to bereflected (inherited) to SD_PC_SET0 and the SD_PC_SET1 inSEPARATE_ACCUMULATION-DISABLE operation. In particular, according to thepresent embodiment, the accumulation value of the uplinkcommunication-related closed-loop power control (CLPC) parameter (e.g.,f_(c)(i)) in the SEPARATE_ACCUMULATION-DISABLE operation can beinitialized or reset due to SEPARATE_ACCUMULATION-ENABLE.

Embodiment 22

According to embodiment 22 of the present invention, it is able toconfigure an accumulation value of uplink communication-relatedclosed-loop power control (CLPC) parameter (e.g., f_(c)(i)) in theSEPARATE_ACCUMULATION-DISABLE operation to be reflected (inherited) toSD_PC_SET0 (i.e., an uplink subframe set having interferencecharacteristic of I_UU) only.

In particular, in terms of SD_PC_SET1 (i.e., an uplink subframe sethaving interference characteristic of I_DU), the accumulation value ofthe uplink communication-related closed-loop power control (CLPC)parameter (e.g., f_(c)(i)) in the SEPARATE_ACCUMULATION-DISABLEoperation can be initialized or reset due toSEPARATE_ACCUMULATION-ENABLE. Moreover, if the accumulation value of theuplink communication-related closed-loop power control (CLPC) parameter(e.g., f_(c)(i)) in SEPARATE_ACCUMULATION-DISABLE operation is reflected(inherited) to the SD_PC_SET0, it is able to configure a result value bywhich a predefined (signaled) weight is multiplied to be reflected(inherited).

Or, it is able to configure an accumulation value of uplinkcommunication-related closed-loop power control (CLPC) parameter (e.g.,f_(c)(i)) in SEPARATE_ACCUMULATION-DISABLE operation to be reflected(inherited) to SD_PC_SET1 (i.e., an uplink subframe set havinginterference characteristic of I_DU) only. In this case, if theaccumulation value of the uplink communication-related closed-loop powercontrol (CLPC) parameter (e.g., f_(c)(i)) inSEPARATE_ACCUMULATION-DISABLE operation is reflected (inherited) to theSD_PC_SET1, it is able to configure a result value by which a predefined(signaled) weight is multiplied to be reflected (inherited).

Embodiment 23

According to embodiment 23 of the present invention, it is able toconfigure an accumulation value of uplink communication-relatedclosed-loop power control parameter (e.g., f_(c)(i)) inSEPARATE_ACCUMULATION-DISABLE operation to be reflected (inherited) toSD_PC_SET0 and the SD_PC_SET1.

In this case, if the accumulation value of the uplinkcommunication-related closed-loop power control parameter (e.g.,f_(c)(i)) in SEPARATE_ACCUMULATION-DISABLE operation is reflected(inherited) to the SD_PC_SET0 and the SD_PC_SET1, it is able toconfigure result values by which predefined (signaled) different (oridentical) weights are multiplied to be reflected (inherited) accordingto an uplink subframe set (i.e., SD_PC_SET0, SD_PC_SET1) having adifferent interference characteristic.

Embodiment 24

According to embodiment 24 of the present invention, an operation ofreflecting (inheriting) an accumulation value of an uplinkcommunication-related closed-loop power control parameter (e.g.,f_(c)(i)) in SEPARATE_ACCUMULATION-DISABLE operation to SD_PC_SET0(i.e., an uplink subframe set having interference characteristic ofI_UU) only can be configured to be restrictively applied to a case thata part (or all) of open-loop (OLPC) parameters (e.g., P_(O) _(_) _(UE)_(_) _(PUSCH,c), P_(O) _(_) _(NOMINAL) _(_) _(PUSCH,c), α_(c)) relatedto the SD_PC_SET0 are identically maintained with previous (i.e.,SEPARATE_ACCUMULATION-DISABLE) values or a case that a part (or all) ofopen-loop (OLPC) parameters related to the SD_PC_SET0 and the SD_PC_SET1are identically maintained with previous (i.e.,SEPARATE_ACCUMULATION-DISABLE) values only afterSEPARATE_ACCUMULATION-ENABLE.

Or, an operation of reflecting (inheriting) an accumulation value of anuplink communication-related closed-loop power control parameter (e.g.,f_(c)(i)) in SEPARATE_ACCUMULATION-DISABLE operation to SD_PC_SET1(i.e., an uplink subframe set having interference characteristic ofI_DU) only can be configured to be restrictively applied to a case thata part (or all) of open-loop (OLPC) parameters (e.g., P_(O) _(_) _(UE)_(_) _(PUSCH,c), P_(O) _(_) _(NOMINAL) _(_) _(PUSCH,c), α_(c)) relatedto the SD_PC_SET1 are identically maintained with previous (i.e.,SEPARATE_ACCUMULATION-DISABLE) values or a case that a part (or all) ofopen-loop (OLPC) parameters related to the SD_PC_SET0 and the SD_PC_SET1are identically maintained with previous (i.e.,SEPARATE_ACCUMULATION-DISABLE) values only afterSEPARATE_ACCUMULATION-ENABLE.

Embodiment 25

According to embodiment 25 of the present invention, it is able toconfigure an accumulation value of uplink communication-relatedclosed-loop power control parameter (e.g., f_(c)(i)) inSEPARATE_ACCUMULATION-DISABLE operation to be reflected (inherited) toan uplink subframe set having a lowest or a relatively low subframe setindex (e.g., 0) only among uplink subframe sets of which interferencecharacteristic is different from each other. For example, it is able toconfigure the lowest subframe set index (e.g., 0) to be assigned to anuplink subframe set having interference characteristic of I_UU or anuplink subframe set having interference characteristic of I_DU.

Or, it is able to configure an accumulation value of uplinkcommunication-related closed-loop power control parameter (e.g.,f_(c)(i)) in SEPARATE_ACCUMULATION-DISABLE operation to be reflected(inherited) to an uplink subframe set having a highest or a relativelyhigh subframe set index (e.g., 1) only among uplink subframe sets ofwhich interference characteristic is different from each other. Forexample, it is able to configure the lowest subframe set index (e.g., 0)to be assigned to an uplink subframe set having interferencecharacteristic of I_UU or an uplink subframe set having interferencecharacteristic of I_DU.

Embodiment 26

According to embodiment 26 of the present invention, it is able toconfigure a base station (or a cell) to inform (signal) a UE of anuplink subframe set index or a UL PC process index (i.e., a specific ULPC process index is interlocked with a specific uplink subframe setindex) to which an accumulation value of an uplink communication-relatedclosed-loop power control parameter (e.g., F_(c)(i)) inSEPARATE_ACCUMULATION-DISABLE operation is inherited (reflected).

In this case, it is able to configure the information to be transmittedin a manner of being included in a usage change message (reconfigurationmessage) (transmitted based on a predetermined period) or it is able toconfigure the information to be transmitted via a predefined(additional) signal (e.g., a higher layer signal or a physical layersignal).

In the following, a method of efficiently initializing (resetting) anaccumulation value of a closed-loop power control (CLPC) parameter(e.g., f_(c)(i)) according to a subframe set under environment to whichan SD_PC mode is applied is explained according to the presentinvention.

Embodiment 27

According to embodiment 27 of the present invention, it is able toconfigure an accumulation value of a closed-loop power control (CLPC)parameter (e.g., f_(c)(i)) according to a subframe set to be initialized(reset) if a change occurs in a part (or all) of parameters described inthe following (and/or if predefined specific information (or message) isreceived) under environment to which an SD_PC mode is applied. In thiscase, an initializing (resetting) operation can be comprehended as theaccumulation value of the closed-loop power control (CLPC) parameter(e.g., f_(c)(i)) according to a subframe set is reconfigured by apredefined (signaled) specific value.

-   -   Change in the number of uplink subframe sets    -   Change in an uplink subframe set pattern    -   Change in whether or not a closed-loop power control (CLPC)        parameter is separately accumulated        (SEPARATE_ACCUMULATION-ENABLE, SEPARATE_ACCUMULATION-DISABLE)        according to a subframe set    -   Change in a part (or all) of open-loop (OLPC) parameters (e.g.,        P_(O) _(_) _(UE) _(_) _(PUSCH,c), P_(O) _(_) _(NOMINAL) _(_)        _(PUSCH,c), ac) (according to a subframe set)    -   When a UE receives a random access response (RAR) message (e.g.,        RAR message for PCell)    -   When a UE receives a usage change message (reconfiguration        message) (based on predetermined period). In this case, an        accumulation value of a closed-loop power control (CLPC)        parameter (e.g., fc(i)) according to a subframe set can be        configured to be restrictively initialized (reset) only when        (updated) UL-DL configuration on a received usage change message        is different from previous (or current) UL-DL configuration.

TPC Command on Subframe-Dependent Uplink Power Control Mode

In a legacy UL-DL configuration #0, an (accumulative and/or absolute)TPC command (e.g., DCI format 0/4/3/3A) received at specific downlinksubframe timing (together with a specific UL index field valueconfiguration (e.g., 11)) is defined to be applied to a plurality of(e.g., 2) uplink subframe timings or uplink data channels transmitted ata plurality of the uplink subframe timings at the same time) Forexample, a UL index field (i.e., 2 bits) of DCI format 0/4 related touplink data channel scheduling and/or uplink transmission power controlis set to “11” (i.e., uplink data channels (PUSCH) are transmitted at 2uplink subframe timings by single uplink scheduling information (ULgrant) received at specific downlink subframe timing) or “10”.

However, if a plurality of the uplink subframe timings respectivelybelong to uplink subframe sets different from each other (e.g.,SD_PCSET0, SD_PC_SET1 (i.e., uplink subframe sets of which interferencecharacteristic is different from each other)) in a state that an SD_PCmode is set, it is unable to precisely identify an uplink subframe setto which the (accumulative and/or absolute) TPC command received at thespecific downlink subframe timing (together with a specific UL indexfield value configuration (e.g., 11)) is targeting.

Hence, configurations for efficiently processing (reflecting) the TPCcommand received at the specific downlink subframe timing (together witha specific UL index field value configuration (e.g., 11)) are proposedin the following. In this case, the configurations described in thefollowing can be configured to be restrictively applied to a specificDCI format (i.e., DCI format 3/3A or DCI format 0/4) only to notifyinformation on the (accumulative and/or absolute) TPC command. And, theconfigurations can be configured to be independently implemented(applied) or can be configured to be implemented (applied) by acombination (e.g., combination of [configuration #B] and [configuration#C]) of the configurations.

Configuration #A: An (accumulative and/or absolute) TPC command receivedat specific downlink subframe timing (together with a specific UL indexfield value configuration (e.g., 11)) may target i) a plurality of(e.g., 2) uplink subframe timings or ii) uplink data channelstransmitted at a plurality of the uplink subframe timings. In this case,if a plurality of the uplink subframe timings respectively belong touplink subframe sets different from each other (e.g., SD_PCSET0,SD_PC_SET1), it is able to configure a UE to apply the TPC command to apredetermined (signaled) UL PC process related to a specific uplinksubframe set only. For example, a base station can inform a UE of anuplink subframe set to which the TPC command received at the specificdownlink subframe timing (together with a specific UL index field valueconfiguration (e.g., 11)) is targeting using a bitmap form of apredetermined length (e.g., if a TPC command is received in a downlinksubframe corresponding to a position where a bit is set to ‘1’, the TPCcommand can be interpreted as being related to SD_PC_SET0).

Configuration #B: An (accumulative and/or absolute) TPC command receivedat specific downlink subframe timing (together with a specific UL indexfield value configuration (e.g., 11)) may target i) a plurality of(e.g., 2) uplink subframe timings or ii) uplink data channelstransmitted at a plurality of the uplink subframe timings). In thiscase, if a plurality of the uplink subframe timings respectively belongto uplink subframe sets different from each other (e.g., SD_PCSET0,SD_PC_SET1), it is able to configure the (identical) TPC command to beapplied to all UL PC processes related to the subframe sets differentfrom each other (according to a legacy configuration).

Configuration #C: An (accumulative and/or absolute) TPC command receivedat specific downlink subframe timing (together with a specific UL indexfield value configuration (e.g., 11)) may target i) a plurality of(e.g., 2) uplink subframe timings or ii) uplink data channelstransmitted at a plurality of the uplink subframe timings. In this case,if a plurality of the uplink subframe timings respectively belong touplink subframe sets different from each other (e.g., SD_PCSET0,SD_PC_SET1), it is able to configure the TPC command to be applied to aUL PC process related to the uplink subframe set only (according to alegacy configuration).

Configuration #D: An (accumulative and/or absolute) TPC command receivedat specific downlink subframe timing (together with a specific UL indexfield value configuration (e.g., 11)) may target i) a plurality of(e.g., 2) uplink subframe timings or ii) uplink data channelstransmitted at a plurality of the uplink subframe timings. In this case,it is able to configure the (identical) TPC command to be applied to allUL PC processes related to the uplink subframe sets different from eachother according to a predefined configuration/rule.

In particular, according to the configuration #D, the (identical) TPCcommand can be applied to all UL PC processes related to the uplinksubframe sets different from each other irrespective of whether or not aplurality of the uplink subframe timings to which the (accumulativeand/or absolute) TPC command received at the specific downlink subframetiming (together with the specific UL index field value configuration(e.g., 11)) is targeting respectively belong to the subframe sets (e.g.,SD_PCSET0 or SD_PC_SET1) different from each other. In this case, a DCIformat in which the (accumulative and/or absolute) TPC command istransmitted can be restricted to a DCI format 3/3A or a DCI format 0/4.

Configuration #E: It is able to configure an (accumulative and/orabsolute) TPC command on a specific DCI format to be applied to all ULPC processes related to uplink subframe sets different from each otheraccording to a predetermined configuration/rule. In this case, a DCIformat in which the (accumulative and/or absolute) TPC command istransmitted can be restricted to a DCI format 3/3A or a DCI format 0/4.

Configuration #F: A field (e.g., 1 bit) for indicating an uplinksubframe set to which a TPC command is targeting can be added to a DCIformat in relation to transmission of information on the TPC command. Inthis case, as a different example, it may be able to implement a form ofreinterpreting a meaning of a legacy field instead of newly adding thefield.

In particular, power control parameter configuration and PHR can beadjusted according to the present invention.

Regarding a power control parameter for two subframe sets, UE can beconfigured with UE-specific P0 and cell-specific α by RRC signaling.When the UE is configured for TDD eIMTA operations, the UE can beconfigured with (up to) two subframe sets. For each subframe set,different P0 and α values can be used, but the relationship between suchlegacy parameters of (e.g., UE-specific P0 and cell-specific α} andnewly configured P0 and α is not clearly defined yet.

Specifically, when a UE is configured with two subframe sets (Set #1 andSet #2), it needs to be decided whether each subframe set in the two-setconfiguration message is always accompanied by the associated PCparameter set.

If it is allowed to reuse the legacy parameters for one of the two sets,it seems needed to have such parameters of P0 and alpha per subframe setbeing optionally present in the relevant RRC signaling of subframe setconfigurations. It means that if such parameters of P0 and alpha are notpresent in a RRC message for a subframe set, the subframe set is linkedto the legacy parameters of {UE-specific P0 and cell-specific alpha} tobe used for UL PC.

If there is a common understanding that same legacy parameters arealways used for Set#1, the PC parameter configuration part can beomitted in the RRC message for Set#1. If the PC parameter configurationis a mandatory part for both sets in the RRC message, the UL PC isalways reset in both sets whenever two subframe sets are configured.

Similarly, in case when a fallback to only one subframe set is indicatedby RRC signaling to the UE, it needs to be decided whether the currentlegacy parameters of {UE-specific P0 and cell-specific α} are applied toall subframes, or new parameters should be signaled to the UE via thefallback message regardless of the current legacy parameters.

Another possible option can be maintaining the parameters of P0 and αfor Set#1 to be inherited and applied to all subframes by the fallbackindication, which in turn means the parameters linked to Set#2 are onlydiscarded once the fallback indication is received. If bothpossibilities need to be supported, it is possible to have the PCparameters to be used when falls back to one subframe set as an optionalone.

In particular, when UE is configured with up to two subframe sets, therelationship between existing legacy parameters of {UE-specific P0 andcell-specific α} and newly configured P0 and α (per subframe set) needsto be clarified. When a fallback to one subframe set is indicated by RRCsignaling to the UE, it needs to be decided whether the existing legacyparameters of {UE-specific P0 and cell-specific α} are applied to allsubframes, or new parameters should be signaled to the UE via thefallback message.

Subsequently, PHR (power headroom report) is explained in more detail.

The current PHR mechanism can allow PHR for two subframe sets. To bespecific, according to the current specification, PHRs are estimated andtransmitted at the same subframe where PUSCH is transmitted. So, foreach subframe set, the PHR is obtained at one subframe belonging to thesubframe set. However, in such operation, there exist some restrictionson obtaining the PHRs for two subframe sets from the perspective of aneNB.

Firstly, there will be an UL resource waste or an UL scheduling overheadincrement to obtain the PHRs for two subframe sets. This is because aneNB can get only PHR for one subframe set at a time. In addition, thisdrawback may also causes an additional problem that it is hard for aneNB to get the PHRs of two subframe sets in time.

Secondly, it is hard for an eNB to infer the PHR value of one subframeset from that of another subframe set. The reason is that the pathlossvalue is in general unknown to an eNB, and if TPC accumulation isenabled, f_(c)(i) in [6] is also unknown to an eNB since a UE may beable to miss TPC command.

To resolve the above-mentioned restrictions of the current PHRmechanism, the PHR enhancement could be needed. Firstly, if the PHR istriggered, it can be interpreted that the PHRs of all subframe sets aretriggered and reported. Here, each PHR value is calculated on the basisof the power control parameter set associated with the each subframeset.

Secondly, with regard to the PHR reporting timing of each subframe set,the following two options can be considered. The first one is that thePHRs of all subframe sets will be reported simultaneously in the samesubframe. The second one is that the PHR of each subframe set will bereported at one subframe which belongs to the each subframe set. Theformer may require more specification works to design a new container(carrying PHRs of multiple subframe sets of a single CC), but it canprovide an eNB with PHRs of all subframe sets in a short time.

Thirdly, if the PHR is triggered, it can be interpreted that therepresentative PHR is reported to an eNB. Here, for example, therepresentative PHR can be defined as the minimum value among PHRs of allsubframe sets. This scheme does not have an impact to other workinggroups.

Regarding the power limitation in an eIMTA-operating system, it needs tobe reminded that subframe-set specific power control is useful inmitigating interferences from pico cells to macro cells in the scenarioof macro-pico adjacent channel. So, PHR enhancement is expected to beuseful more for macro UEs in that scenario.

In particular, according to the present invention, if PHR is triggeredbased on the PH reporting procedures, PHs of all subframe sets aretriggered and reported. With regard to the PHR reporting timing of eachsubframe set, the two options can be considered; the first option isthat the PHRs of all subframe sets will be reported simultaneously inthe same subframe, while the second option is that the PHR of eachsubframe set will be reported at one subframe which belongs to the eachsubframe set. In addition, if the PHR is triggered, it can beinterpreted that the representative PHR, e.g., the minimum value amongPHRs of all subframe sets, is reported to an eNB.

In the present invention, if an accumulation value of a closed-looppower control parameter (e.g., f_(c)(i)) related to a specific uplinksubframe set is reflected (inherited) to a different uplink subframeset, it indicates that the accumulation value of the closed-loop powercontrol parameter (e.g., f_(c)(i)) of a UL PC process interlocked withthe specific uplink subframe set is inherited (reflected) to an initialvalue (e.g., f_(c)(0)) of accumulation of the closed-loop power controlparameter (e.g., f_(c)(i)) of a UL PC process interlocked with thedifferent uplink subframe set.

And, the aforementioned embodiments of the present invention can beextensively applied to at least one selected from the group consistingof an SD_PC mode, a non-SD_PC mode, a SEPARATE_ACCUMULATION-DISABLE modeand a SEPARATE_ACCUMULATION-ENABLE mode.

And, the aforementioned embodiments of the present invention can also beextensively applied to a case that the number of uplink subframe sets towhich an independent UL PC process is applied in the SD_PC mode (havingdifferent interference characteristic) is set to 3 or more.

And, the aforementioned embodiments of the present invention can also beextensively applied to i) a case that a change occurs in the number ofuplink subframe sets and/or ii) a case that a change occurs in an uplinksubframe set pattern and/or iii) a case that a change occurs on whetheror not a closed-loop power control (CLPC) parameter according to asubframe set is separately accumulated (SEPARATE_ACCUMULATION-ENABLE,SEPARATE_ACCUMULATION-DISABLE) and/or iv) a case that a change occurs ina part (or all) of open-loop (OLPC) parameters (e.g., P_(O) _(_) _(UE)_(_) _(PUSCH,c), P_(O) _(_) _(NOMINAL) _(_) _(PUSCH,c), αc) (accordingto a subframe set) and/or v) a case that a change occurs on whether ornot a UE receives a random access response (RAR) message (e.g., RARmessage for PCell).

Since the aforementioned embodiments/configurations are capable of beingincluded as one of methods of implementing the present invention, it isapparent that the embodiments/configurations can be considered as a sortof proposed schemes. And, the embodiments of the present invention canbe independently implemented and can be implemented in a combinationform of a part of the embodiments.

And, the aforementioned embodiments of the present invention can also beextensively applied to power control related to an uplink data channel(PUSCH) and/or an uplink control channel (PUCCH) and/or a soundingreference signal (SRS).

And, the aforementioned embodiments of the present invention can beconfigured to be restrictively applied only when a dynamic change modeof a radio resource usage is set (e.g., when a base station (or cell)sets a dynamic change mode of a radio resource usage to a UE via apredetermined signal).

And, the aforementioned proposed schemes can be configured to berestrictively applied only i) when a closed-loop parameter (or anaccumulative calculation mode (accumulative TPC command) of a TPCcommand (e.g., f_(c)(i)) in which (higher layer signal-relatedparameter) “Accumulation-enabled” is received is designated, ii) when aclosed-loop parameter (or a non-accumulative calculation mode (absoluteTPC command) of a TPC command (e.g., f_(c)(i)) in which“Accumulation-enabled” is received is designated, iii) when aclosed-loop parameter (or a TPC command) is received via a specific DCIformat (e.g., DCI format 0/4 or DCI format 3.3A), iv) when a mode oftransmitting PUSCH and PUCCH at the same time is set, v) when a mode oftransmitting PUSCH and PUCCH at the same time is not set. Theaforementioned proposed schemes can be configured to be restrictivelyapplied to vi) a PCell or a Scell or vii) a specific cell (or acomponent carrier (CC)) to which a dynamic change mode of a radioresource usage is set only.

Moreover, it is able to configure a base station to inform a UE ofinformation on whether to apply the aforementionedembodiments/configurations of the present invention or information onthe aforementioned embodiments/configurations of the present inventionvia a predetermined signal (e.g., a physical layer signal or a higherlayer signal).

FIG. 9 is a block diagram for a communication device according to oneembodiment of the present invention.

Referring to FIG. 9, a communication device 900 may include a processor910, a memory 920, an RF module 930, a display module 940, and a userinterface module 950.

Since the communication device 900 is depicted for clarity ofdescription, prescribed module(s) may be omitted in part. Thecommunication device 900 may further include necessary module(s). And, aprescribed module of the communication device 900 may be divided intosubdivided modules. A processor 910 is configured to perform anoperation according to the embodiments of the present inventionillustrated with reference to drawings. In particular, the detailedoperation of the processor 910 may refer to the former contentsdescribed with reference to FIG. 1 to FIG. 8.

The memory 920 is connected with the processor 910 and stores anoperating system, applications, program codes, data, and the like. TheRF module 930 is connected with the processor 910 and then performs afunction of converting a baseband signal to a radio signal or a functionof converting a radio signal to a baseband signal. To this end, the RFmodule 930 performs an analog conversion, amplification, a filtering,and a frequency up conversion, or performs processes inverse to theformer processes. The display module 940 is connected with the processor910 and displays various kinds of informations. And, the display module940 can be implemented using such a well-known component as an LCD(liquid crystal display), an LED (light emitting diode), an OLED(organic light emitting diode) display and the like, by which thepresent invention may be non-limited. The user interface module 950 isconnected with the processor 910 and can be configured in a manner ofbeing combined with such a well-known user interface as a keypad, atouchscreen and the like.

The above-described embodiments correspond to combinations of elementsand features of the present invention in prescribed forms. And, therespective elements or features may be considered as selective unlessthey are explicitly mentioned. Each of the elements or features can beimplemented in a form failing to be combined with other elements orfeatures. Moreover, it is able to implement an embodiment of the presentinvention by combining elements and/or features together in part. Asequence of operations explained for each embodiment of the presentinvention can be modified. Some configurations or features of oneembodiment can be included in another embodiment or can be substitutedfor corresponding configurations or features of another embodiment. And,it is apparently understandable that an embodiment is configured bycombining claims failing to have relation of explicit citation in theappended claims together or can be included as new claims by amendmentafter filing an application.

Embodiments of the present invention can be implemented using variousmeans. For instance, embodiments of the present invention can beimplemented using hardware, firmware, software and/or any combinationsthereof. In the implementation by hardware, a method according to eachembodiment of the present invention can be implemented by at least oneselected from the group consisting of ASICs (application specificintegrated circuits), DSPs (digital signal processors), DSPDs (digitalsignal processing devices), PLDs (programmable logic devices), FPGAs(field programmable gate arrays), processor, controller,microcontroller, microprocessor and the like.

In case of the implementation by firmware or software, a methodaccording to each embodiment of the present invention can be implementedby modules, procedures, and/or functions for performing theabove-explained functions or operations. Software code is stored in amemory unit and is then drivable by a processor. The memory unit isprovided within or outside the processor to exchange data with theprocessor through the various means known in public.

While the present invention has been described and illustrated hereinwith reference to the preferred embodiments thereof, it will be apparentto those skilled in the art that various modifications and variationscan be made therein without departing from the spirit and scope of theinvention. Thus, it is intended that the present invention covers themodifications and variations of this invention that come within thescope of the appended claims and their equivalents.

INDUSTRIAL APPLICABILITY

The aforementioned embodiments of the present invention can be appliedto various mobile communication systems.

1. A method of controlling uplink transmission power by a user equipmentin a wireless communication system, comprising the steps of:transmitting an uplink signal according to an uplink-downlinkconfiguration predetermined to a serving cell; receiving firsttransmission power control information on a first uplink subframe setand second transmission power control information on a second uplinksubframe set from the serving cell; and transmitting an uplink datachannel (physical uplink shared channel, PUSCH) in a specific subframecontained in the second uplink subframe set according to the secondtransmission power control information, wherein the second uplinksubframe set comprises at least one or more uplink subframes designatedby higher layer signaling among a plurality of uplink subframesaccording to the predetermined uplink-downlink configuration.
 2. Themethod of claim 1, wherein the second transmission power controlinformation comprises a value indicating a current PUSCH power controladjustment state for an index of the specific subframe.
 3. The method ofclaim 2, wherein if information on the second uplink subframe set isreceived, the current PUSCH power control adjustment state is reset. 4.The method of claim 2, wherein if information on the second uplinksubframe set is received, the current PUSCH power control adjustmentstate is set to
 0. 5. The method of claim 1, wherein the first uplinksubframe set corresponds to a subframe of which a usage of a radioresource is configured not to be changed and wherein the second uplinksubframe set corresponds to a subframe of which a usage of a radioresource is configured to be changed.
 6. The method of claim 1, whereinthe first uplink subframe set and the second uplink subframe set aredifferent from each other in an interference characteristic with aneighbor cell.
 7. The method of claim 1, wherein the second uplinksubframe set is indicated by a usage change message.
 8. The method ofclaim 1, wherein the specific subframe is indicated by downlink controlinformation in a DCI format 0/4.
 9. A user equipment controlling uplinktransmission power in a wireless communication system, comprising: aradio frequency unit; and a processor, the processor configured totransmit an uplink signal according to an uplink-downlink configurationpredetermined to a serving cell, the processor configured to receivefirst transmission power control information on a first uplink subframeset and second transmission power control information on a second uplinksubframe set from the serving cell, the processor configured to transmitan uplink data channel (physical uplink shared channel (PUSCH)) in aspecific subframe contained in the second uplink subframe set accordingto the second transmission power control information, wherein the seconduplink subframe set comprises at least one or more uplink subframesdesignated by higher layer signaling among a plurality of uplinksubframes according to the predetermined uplink-downlink configuration.10. The user equipment of claim 9, wherein the second transmission powercontrol information comprises a value indicating a current PUSCH powercontrol adjustment state for an index of the specific subframe.
 11. Theuser equipment of claim 10, wherein if information on the second uplinksubframe set is received, the current PUSCH power control adjustmentstate is reset.
 12. The user equipment of claim 10, wherein ifinformation on the second uplink subframe set is received, the currentPUSCH power control adjustment state is set to
 0. 13. The user equipmentof claim 9, wherein the first uplink subframe set corresponds to asubframe of which a usage of a radio resource is configured not to bechanged and wherein the second uplink subframe set corresponds to asubframe of which a usage of a radio resource is configured to bechanged.
 14. The user equipment of claim 9, wherein the first uplinksubframe set and the second uplink subframe set are different from eachother in an interference characteristic with a neighbor cell.
 15. Theuser equipment of claim 9, wherein the second uplink subframe set isindicated by a usage change message.
 16. The user equipment of claim 9,wherein the specific subframe is indicated by downlink controlinformation in a DCI format 0/4.